Gift  of 
Dr.   Dain  L.    Tasker 


SYPHILIS 


NERVOUS   SYSTEM. 


BY   THE   SAME    AUTHOR. 


Diseases  of  The  Nervous  System. 


Second  Edition.    2  Vols.    Illustrated. 


VOLUME  I.  DISEASES  OF  THE  NERVES  AND 
SPINAL  CORD. — 624  pages.  180  Illustrations, 
including  Three  Hundred  and  Sixty-seven  Fig- 
ures. Octavo. 

Just  Beady.     Handsome  Cloth,  $3.50. 

VOLUME   II.     DISEASES   OF  THE   BRAIN  AND 
•    CRANIAL    NERVES  ;    GENERAL   AND    FUNC- 
TIONAL DISEASES. — With  a  large  number  of 
Illustrations.     Octavo.  Nearly  Ready. 

The  whole  work  has  been  very  thoroughly  re- 
vised and  much  new  material  has  been  added. 


c  VPH  H  I  <x 

o  i  rni^io  ?JRGf, 


AND   THE 


NERVOUS  SYSTEM 


BEING   A 


REVISED  REPRINT  OF  THE  LETTSOMIAN  LECTURES  FOR  1890 

DELIVERED   BEFORE  THE   MEDICAL 

SOCIETY  OF  LONDON. 


/  BY 

W.   R.  (J6WERS,  M.D.,  F.R.C.P.,  F.R.S., 

CONSULTING     PHYSICIAN    TO    UNIVERSITY    COLLEGE     HOSPITAL,    PHYSICIAN    TO    THE 
NATIONAL  HOSPITAL  FOB  THE   PARALYZED  AND  EPILEPTIC,  ETC. 


PHILADELPHIA: 
P.    BLAKISTON,   SON    &    CO., 

1012   WALNUT   STREET. 
1892. 


COPYRIGHT,  1892,  BY  P.  BLAKISTON,  SON  &  Co. 


PRESS    OF   WM.    F      FELL   &    CO.. 


PHILADELPHIA.    PA., 
U.    S.    A. 


PREFACE. 


These  lectures,  delivered  three  years  ago,  are  now 
reprinted  on  account  of  the  frequency  with  which  I 
find  it  necessary  to  refer  to  statements  made  in  them, 
and  the  inconvenience  of  being  obliged  to  refer  a 
reader  to  the  Medical  Journals  in  which  the  lectures 
originally  appeared.  Two  translated  reprints  have 
been  published,  and  this  renders  their  reproduction  in 
the  English  language  the  more  desirable.  Moreover,  I 
have  taken  the  opportunity  of  carefully  revising  them, 
and  have  made  a  large  number  of  additions.  These, 
although  not  obtrusive  or  extensive,  will,  I  hope,  be 
found  to  increase  the  practical  value  of  what  is  said, 
and  may  serve  to  bring  the  lectures  up  to  the  level 
of  our  present  knowledge  if  they  are  below  this  in  their 
original  form.  At  the  same  time,  their  scope  and  char- 
acter make  the  need  for  such  additions  insignificant. 
Their  chief  object  is  to  enable  those  who  read  them 
to  grasp  more  firmly  the  cases  they  meet  with,  and  to 
understand  better  the  methods  of  dealing  with  the 
disease  in  practical  thought  and  actual  work. 

My  thanks  are  due  Dr.  D.  D.  Stewart,  of  Philadel- 
phia, for  assistance  in  reading  proof,  and  for  preparing 
the  index. 

Queen  Anne  St.,  London, 
October,  1892. 


TABLE  OF  CONTENTS. 


LECTURE  I. 

THE  ULTIMATE  PATHOLOGY  OF  SYPHILIS. 
The  Actual  Pathological  Position  and  Macroscopic  (non-histo- 
logic)  Character  of  Syphilitic  Tissue-formations  ;  Their  Divi- 
sion into  Classes, — Specific  and  Non-special. — General  Con- 
sideration of  These,  Their  Situation  and  Effects,  Direct  and 
Remote  ;  the  Specific  or  Neoplastic,  Consisting  of  Gummata 
and  Growths  in  the  Arterial  Walls,  and  the  Pathologically 
Non-special  or  Inflammatory  Lesions. — The  Question  of  Evi- 
dence as  an  Aid  to  the  Diagnosis  of  Inflammatory  or  Patho- 
logically Non-specific  Lesions. — Evidence  of  Sequence  and 
that  of  Therapeutics  as  an  Aid  to  the  Proof  of  Causation. — 
The  Relations  of  Nerve-degenerations  to  Syphilis. — Analogy 
Between  the  Effect  of  Certain  Poisons,  Chemical  and  Organ- 
ized, and  that  of  Syphilis.— Strumpell's  Hypothesis,  .  .  .  .  9-54 

LECTURE  II. 

THE  ORIGIN  OF  FUNCTIONAL  NEKVOUS  DISOEDEES  ATTRIBUTED 
TO  SYPHILIS  ON  IMPERFECT  EVIDENCE. 

Considerations  in  Outline  of  the  Possible  and  Probable  Diag- 
nosis of  Syphilis  of  the  Nervous  System  Determined  by  the 
Situation  and  Nature  of  the  Lesions,  and  the  Character  and 
Course  of  the  Symptoms. — Symptomatology  and  Diagnosis  of 
Some  Syphilitic  Processes  Affecting  the  Nervous  System, 
such  as  Gummata,  Chronic  Local  Cerebral  Meningitis,  and 
Arterial  Disease  with  its  Sequences,  Thrombosis  with  Ne- 
crotic  Softening  of  the  Brain. — Ocular  Palsies. — The  Import- 
ance of  Accuracy  of  Diagnosis  in  Syphilitic  Disease  of  the 
Nervous  System, 55-90 

vii 


Vlll  CONTENTS. 

LECTURE  III. 

THE  ESSENTIAL   PRINCIPLES  UNDERLYING   THE    PROGNOSIS   OF 

SYPHILITIC  DISEASE  OF  THE  NERVOUS  SYSTEM,  AND 

THEIR  EFFECT  UPON  THE  SPECIAL  PROGNOSIS 

OF  THE  CHIEF   LESIONS. 

The  Prognosis  a  Matter  of  Special  Consideration  of  Individual 
Cases,  as  is  also  Diagnosis. — Symptoms  of  Syphilitic  Disease 
of  the  Nervous  System  Depend  not  on  the  Specific  Process, 
but  on  the  Simple  Alterations  this  Produces  in  Nerve-tissue. 
— As  Treatment  Exerts  a  Direct  Effect  on  the  Specific  Process 
Only,  the  Persistence  of  Symptoms  Despite  Treatment  Indi- 
cates the  Persistence  of  Damage  to  the  Nerve  Elements,  and 
not  of  the  Luetic  Lesion  Producing  the  Damage. — Special 
Prognosis  of  the  Chief  Luetic  Affections. — Modifications  of 
Prognosis  Entailed  by  Symptoms  of  Irritation  Caused  by 
Certain  Lesions. — Syphilis  an  Incurable  Disease — this  State- 
ment Consistent  with  the  Recognition  of  the  Fact  that  the 
Lesions  of  Syphilis  are  Readily  Removed  by  Treatment. — 
Respective  Power.of  Mercury  and  of  Potassium  Iodide  in  the 
Treatment  of  Syphilitic  Diseases  of  the  Nervous  System. — 
How  these  Drugs  are  best  Employed. — Efficient  Measures  of 
Prevention  and  of  Arrest  of  Syphilis  not  yet  at  Hand. — Un- 
broken Chastity  the  only  Certain  Prevention, 91-127 

INDEX,  128 


SYPHILIS 


NERVOUS   SYSTEM 


LECTURE  I. 

MR.  PRESIDENT  AND  GENTLEMEN, — Permit  me  first 
to  tender  to  you,  Sir,  and  the  Council,  my  thanks  for 
selection  to  the  post  of  Lettsomian  Lecturer  to  this 
Society,  a  post  around  which  cluster  so  many  honor- 
able associations.  The  duty  which  that  selection  lays 
upon  me,  and  which  I  have  now  to  attempt  to  dis- 
charge, has  difficulties  of  its  own.  This  Society  consti- 
tutes an  audience  with  the  widest  professional  interests, 
but  above  all  with  an  interest  in  the  practical  aspects 
of  medical  science.  This  characteristic  has  been  handed 
down  through  successive  generations  of  its  Fellows, 
from  the  time  when  theory  bore  a  much  smaller  pro- 
portion to  practice  than  it  does  now.  It  is  not  one  that 
should  be  lightly  esteemed  or  hastily  discarded,  espec- 
ially in  these  days,  when  the  "  scientific  imagination  " 
is  apt  to  wander  far  and  free.  The  subject  to  which  I 
2  9 


10  LETTSOMIAN    LECTURES   ON   SYPHILIS 

propose  to  ask  your  attention  is  one  in  which,  more 
perhaps  than  in  any  other,  the  two  great  branches  of 
the  profession  join  hands  in  mutual  supplement  of 
work.  This  co-operation  is  the  more  important  because 
the  disease  we  are  to  consider  turns  to  each  a  differ- 
ent face.  To  the  surgeon  the  processes  of  syphilis 
are  for  the  most  part  open  and  manifest ;  to  the  physi- 
cian they  are  secret ;  its  ways  are  obscure,  its  language 
is  seldom  unequivocal. 

This  subject  has,  indeed,  once  already  been  made 
that  of  the  Lettsomian  Lectures.  Those  of  my  distin- 
guished predecessor,  Dr.  Broa'dbent,  together  with  the 
almost  simultaneous  work  of  Dr.  Buzzard,  were  the 
means  of  first  diffusing  widely,  in  this  county,  a  knowl- 
edge of  the  extensive  influence  of  syphilis  on  the  nervous 
system.  But  the  fifteen  years  that  have  since  passed 
have  been  prolific  in  additions  to  our  knowledge,  and 
the  time  seems  ripe  for  a  fresh  review  of  at  least  some 
aspects  of  the  subject.  Not  only  are  there  many  new 
facts  that  deserve  notice,  but  there  are  many  doubtful 
points  that  need  consideration.  If  it  is  desirable  to  re- 
view our  positive  knowledge,  it  is  not  less  important 
clearly  to  define  or  even  to  discern  its  limits.  There  is 
perhaps  no  subject  on  which  there  is  so  much  of  what 
may  be  termed  (if  the  convenient  contradiction  is  per- 
mitted) uncertain  knowledge — in  which  there  are  so 
many  opinions  that  rest  on  "no  secure  foundation,  and 
yet  are  accepted  as  true — so  many  mere  hypotheses  that 
are  put  forward  and  received  as  more  than  hypothetical ; 
so  much  that  is  possibly  true,  and  yet  is  still  unsupported 
by  any  real  evidence.  Hence  it  seems  especially  desir- 


AND   THE   NERVOUS   SYSTEM.  11 

able  to  consider  the  evidence  that  has  been  or  may  be 
obtained  as  to  the  relation  to  syphilis  of  many  of  the 
diseases  of  the  nervous  system.  In  doing  so,  we  shall 
learn  something  of  them,  and  see  how  we  may  learn 
more.  There  are  also  practical  questions  in  diagnosis 
and  prognosis  that  need  consideration.  Lastly,  there 
are  questions  in  treatment  on  which  current  opinion  is 
divided,  in  some  cases  widely  divided;  a  discussion  of 
these,  even  if  partial,  may  be  of  service  by  drawing  to 
them  the  attention  of  the  many,  which  they  at  present 
receive  only  from  a  few.  These,  then,  are  the  topics  to 
which  I  propose  to  ask  your  attention. 

I  dare  not  depart  from  the  time-honored  custom  of  a 
preliminary  apology,  especially  as  I  feel  that  an  apology 
is  not  unneeded.  Indeed,  that  I  may  be  quite  on  the 
safe  side  alike  of  custom  and  of  conscience,  I  will  be 
bold  in  my  humility,  and  offer  you  two  apologies.  First, 
you  have  a  right  to  expect  from  a  Lettsomian  lecturer 
something  new,  some  definite  addition  to  our  knowl- 
edge. This  reasonable  expectation  I  fear  I  must  dis- 
appoint. It  is  scarcely  compatible  with  the  chief  object 
that  I  desire  to  attempt.  My  second  apology  arises 
from  the  fact  that  we  cannot  separate  one  part  of  a  dis- 
ease from  the  rest.  In  considering  syphilis  as  it  affects 
the  nervous  system,  and  especially  the  question  of  evi- 
dence, I  cannot  avoid  alluding  to  points  in  its  history 
that  I  am  not  competent  to  discuss.  In  this  also  I 
must  ask  your  indulgence,  and  it  may  save  time  and 
words  if,  once  for  all,  I  beg  you  to  impute  to  me  all  due 
diffidence  and  hesitation  wherever  they  are  seemly,  even 


12  LETTSOMIAN    LECTURES   ON    SYPHILIS 

though,  in  the  exigence  of  the  moment,  they  may  not 
be  manifest. 

Among  the  visceral  effects  of  syphilis  those  on  the 
nervous  system  stand  first  in  extent,  variety,  frequency, 
and  gravity.  Considering  this  fact,  it  may  seem  strange 
that  our  knowledge  of  these  lesions  should  have  been 
of  such  slow  growth  and  late  development,  and  that  so 
vast  a  range  of  syphilitic  influence  was  scarcely  sus- 
pected thirty  years  ago.  But  we  must  not  forget  that 
thirty  years  hence  some  future  Lettsomian  lecturer,  now 
playing  with  his  toys,  may  make '  the  same  remark  of 
the  knowledge  of  the  present  day.  The  cause  that  has 
hindered  our  acquaintance  with  these  diseases  is  not 
far  to  seek.  It  is  a  cause  that  we  cannot  and  must  not 
hope  to  be  lessened  in  the  future — the  old  and  inevit- 
able antagonism  between  pathology  and  therapeutics. 
Each  flourishes  at  the  expense  of  the  other.  The  ends 
for  which  we  gain  our  knowledge  are  the  chief  obstacle  to 
its  acquisition.  We  know  most  about  the  pathology  of 
the  diseases  that  we  fail  to  cure.  In  proportion  as  we 
are  successful  in  treatment  we  are  dependent  on  the 
"  chapter  of  accidents"  for  information  as  to  the  real 
nature  of  the  disease.  This  influence  has  affected 
syphilis  more  than  most  other  maladies. 

The  "  ultimate  pathology  "  of  syphilis,  even  in  its 
special  relations,  is  beyond  the  limit  I  have  set  to  the  sub- 
ject of  these  lectures.  That  the  cause  of  syphilis  is  a  mi- 
cro-organism can  scarcely  be  doubted  by  any  one  who  has 
followed,  even  at  a  distance,  those  discoveries  that  have 
transformed  so  much  of  our  pathology,  although  it  may 


AND   THE    NERVOUS   SYSTEM.  13 

reasonably  be  doubted  whether  the  organism  itself  has 
yet  been  detected.  It  is  also  highly  probable  that  the 
organism  is  the  immediate  cause  of  most  lesions,  which 
can  be  promptly  influenced  by  the  treatment  known  as 
"  anti-syphilitic."  But  beyond  this  I  must  not  attempt 
to  discuss  the  pathology  of  the  disease.  It  was  part  of 
my  original  intention  to  endeavor  to  confer  some  sem- 
blance of  vitality  on  the  dry  bones  I  have  to  offer  you, 
by  indicating  the  form  in  which  some  of  the  pathologi- 
cal problems  of  syphilis  present  themselves  at  the 
present  day,  and  the  kind  of  answer  we  may  reasonably 
expect  from  the  knowledge  that  we  hope  the  near  future 
has  in  store.  But  for  a  profitable  discussion  of  such 
questions,  however  brief,  the  time  is  not  yet  ripe.  At 
present  we  have  no  guide  but  analogy,  certainly  not 
close,  and  possibly  misleading,  and  I  desire  to  avoid 
the  region  of  mere  analogy  and  of  pure  speculation. 

Permit  me,  however,  at  the  outset,  to  remind  you  of 
certain  general  considerations  regarding  the  effects  of 
syphilis, — considerations  that  are  not  speculative,  but 
are  merely  abstract  and  familiar  to  you,  certainly  in 
fact,  and  probably  in  form.  If  we  compare  the  various 
syphilitic  lesions,  not  limiting  our  view  to  any  single 
organ,  we  may  discern  in  them  two  elements — a  process 
of  inflammation,  and  a  process  of  tissue-formation.  It 
might  seem  more  accurate  to  call  the  former  the  "  con- 
gestive "  element,  since  tissue-formation  is  so  often  a 
part  of  the  process  of  inflammation,  but  the  term 
"  congestion "  involves  a  limitation,  and  is  scarcely 
wide  enough  for  the  purpose.  We  can  mentally  distin- 
guish these  two  elements,  and  the  distinction  is  aided 


14  LETTSOMIAN    LECTURES   ON   SYPHILIS 

by  the  fact  that  they  are  combined  in  various  degrees 
in  the  different  lesions.  The  process  of  tissue-forma- 
tion is  seen,  in  almost  a  pure  form,  in  syphilomata,— 
"  gummata,"  as  they  are  called  from  their  gluey  aspect. 
In  these  no  more  of  the  congestive  element  is  to  be 
discerned  than  in  most  other  tumors.  On  the  other 
hand,  the  inflammatory  or  congestive  element  is  almost 
or  quite  pure  in  many  of  the  early  skin  eruptions,  in 
some  cases  of  iritis,  and  in  man}'  other  lesions.  Gen- 
erally the  two  elements  are  combined,  and  the  most 
common  condition  is  that  often  termed  "  hyperplastic 
inflammation."  Sometimes  the  combination  is  such 
that  it  is  not  easy  to  decide  in  which  class  a  lesion 
should  be  placed,  whether  it  should  be  regarded  as  a 
hyperplastic  inflammation  or  as  a  diffuse  gumma. 

If  we  survey  the  course  of  active  syphilis,  there 
seems  to  be  a  tendency  for  the  congestive  or  inflamma- 
tory element  to  preponderate  in  the  early  lesions,  and 
the  tissue-formation  in  the  later.  At  the  same  time,  the 
earliest  lesions,  the  primary  induration  and  the  enlarge- 
ment of  the  nearer  glands,  are  apparent  exceptions  to 
this  law — exceptions  that  will  have  to  be  considered 
whenever  wider  and  deeper  knowledge  brings  with  it 
the  possibility  of  framing  an  adequate  hypothesis  as  to 
the  real  pathology  of  the  disease,  and  the  relation  of 
the  virus  to  the  several  lesions. 

It  has,  indeed,  been  suggested  that  there  is  no  real 
difference  between  these  two  elements.  The  tissue 
formed  in  syphilitic  processes  differs  but  little  from 
that  formed  in  ordinary  inflammation,  and  inasmuch 
as  it  is  combined  in  varying  quantity  with  the  signs  of 


AND    THE    NERVOUS   SYSTEM.  15 

inflammation,  it  is  urged  that  even  the  gumma  has 
closer  affinities  with  inflammatory  products  than  with 
the  true  new  growths.  But  the  admission  of  this 
opinion  (if  it  is  justified)  does  not  preclude  the  dis- 
tinction of  the  two  conditions,  for  it  is  often  well  to 
distinguish  when  we  have  no  right  to  divide.  The 
distinction  seems  to  be  justified  if  each  condition  may 
exist  so  far  alone  that  we  cannot  clearly  discern  the 
other. 

Whatever  be  the  real  pathological  position  of  the 
tissue  formed,  it  presents  certain  characters  not  found 
in  the  same  degree  in  ordinary  inflammatory  products, 
and  it  is  very  important  to  keep  these  in  mind.  First, 
the  peculiarity  of  aspect  when  of  recent  formation,  to 
which  the  name  "  gumma  "  is  due.  Secondly,  the  ten- 
dency to  undergo  certain  changes — for  the  tissue-ele- 
ments to  perish  in  caseation,  or  else  to  undergo  a  change 
into  a  dense  contracting  fibrous  tissue.  The  gluey 
aspect  and  the  caseation  constitute  the  most  important 
characters  by  which  this  tissue  can  be  identified.  The 
tendency  to  degeneration  is  so  widely  but  unequally 
diffused  through  a  mass,  that  the  cheesy  change  usually 
begins  at  many  places.  This  tendency  to  multiple 
caseation,  and  the  irregular  areas  thus  produced,  con- 
stitute the  most  important  criterion  of  the  nature  of 
the  tissue,  when  the  "  gummy  "  aspect  has  ceased  to  be 
distinctive.  Lastly,  the  tendency  to  change  to  a  con- 
tracting fibrous  tissue  is  of  extreme  importance  in  rela- 
tion to  the  effects  produced — by  which  the  lesion  is 
manifested.  This  fibrous  change  often  takes  place  in 
the  tissue  at  the  surface  of  a  gumma,  as  part  of  its 


16  LETTSOMIAN    LECTURES   ON   SYPHILIS 

degenerative  or  cicatricial  changes,  and  it  is  probably 
this  that  has  given  rise  to  the  erroneous  statement 
sometimes  made,  that  a  capsule  is  characteristic  of  these 
growths.  It  may  also  occur  throughout  the  new  for- 
mation, as  in  the  inflammation  of  the  dura  mater  which 
surrounds  the  spinal  cord  with  a  sheath  of  this  dense 
tissue. 

We  may  divide  syphilitic  lesions  into  certain  classes, 
according  to  our  knowledge  of  their  pathological  char- 
acters, and  we  may  expect  to  find  these  classes  repre- 
sented in  the  nervous  system.  First,  there  are  morbid 
processes  with  characters  that  are  peculiar,  processes 
due  to  no  other  cause.  Secondly,  there  are  processes 
that  are  not  peculiar ;  so  far  as  we  can  see,  they  resem- 
ble those  that  are  due  to  other  causes,  although  they 
are  produced  by  syphilis.  Some  of  this  second  class, 
however,  although  not  special  in  pathological  charac- 
ters, are  yet,  when  due  to  syphilis,  peculiar  in  their  seat 
and  distribution.  Others  have  not  even  this  peculiarity, 
but  may  be  described  as  lesions  due  to  many  causes, 
one  of  which  is  syphilis.  I  do  not  say  they  are  not 
really  special  and  peculiar  ;  I  only  say  that  we  cannot 
discern  the  peculiarity.  Outside  the  nervous  system 
we  see  many  examples  of  these  varieties.  They  are 
conspicuous,  for  instance,  in  the  skin.  A  gumma, 
ulcerating  in  a  serpiginous  manner,  is  an  example  of  a 
truly  special  lesion.  Many  other  cutaneous  syphilides, 
such  as  roseola  and  psoriasis,  however,  have  no  patho- 
logical peculiarity,  although  most  of  them,  when  syph- 
ilitic, are  peculiar  in  distribution.  Many  cases  of  syph- 
ilitic iritis  are  special  in  aspect,  but  others  present  no 


AND   THE    NERVOUS    SYSTEM.  17 

peculiarity  to  distinguish  them  from  inflammation  of 
the  iris  due  to  other  causes.  Thus  simple  iritis,  simple 
so  far  as  we  can  see,  has  several  causes,  of  which  syph- 
ilis is  one.  Speaking  generally,  the  more  the  conges- 
tive or  inflammatory  element  preponderates  in  a  lesion, 
the  less  special  are  its  pathological  features.  These 
depend  chiefly  on  the  element  of  tissue-formation. 
Necessarily  also,  as  the  latter  needs  time  for  its  produc- 
tion, the  more  acute  a  syphilitic  inflammation  is,  the 
less  are  its  features  distinctive.  This  is,  I  think,  a  very 
important  consideration. 

It  is  desirable  to  keep  this  classification  in  mind  in 
considering  the  lesions  of  the  nervous  system,  because 
the  evidence  as  to  the  syphilitic  nature  of  a  lesion  nec- 
essarily differs  in  the  various  classes,  and  it  will  be 
desirable  to  adopt  this  classification  in  reviewing  the 
several  lesions  and  the  evidence  regarding  their  nature. 
I  must  pass  unnoticed  those  that  are  caused  by  bone- 
disease. 

We  begin,  then,,  with  the  lesions  of  which  syphilis  is 
the  only  cause.  They  possess  distinctive  characters, 
and  it  is  found  that  syphilis  is  their  invariable  antece- 
dent. It  ean  be  traced  in  a  large  proportion  of  the 
cases,  and  the  more  thorough  our  knowledge  of  the 
individuals,  the  smaller  is  the  proportion  in  which  the 
evidence  of  syphilis  is  not  clear.  On  the  other  hand, 
those  lesions  are  never  met  in  cases  in  which  syphilis 
can  be  excluded  with  certainty.  From  their  special 
characters  they  may  be  termed  "  specific  "  lesions.  We 
need  this  term  for  them,  and  it  is  a  misfortune  that  the 
word  has  come  to  be  used  in  a  wider  sense,  as  a  euphem- 


18  LETTSOMIAN   LECTURES   ON   SYPHILIS 

ism  for  "  syphilitic."  For  this,  moreover,  there  is  a 
word  which  might  with  advantage  become  as  current 
here  as  it  is  in  Germany — "  luetic."  I  propose,  there- 
fore, to  use  the  term  "  specific  "  in  the  sense  of  a  lesion 
that  is  special,  not  only  in  its  causation,  but  also  in  its 
characters. 

These  truly  "  specific  "  lesions  I  must  pass  over  with 
merely  a  brief  mention,  because  they  are  the  best  known 
of  the  effects  of  syphilis,  regarding  which  there  is  least 
room  for  question.  It  will  be  remembered  that  I  am 
now  dealing  only  with  pathology  ;  we  shall  have  again 
to  consider  these  lesions  in  regard  to  practical  diagnosis, 
in  which  they  furnish  many  important  problems. 

First,  there  are  the  syphilitic  growths,  gummata,  cir- 
cumscribed masses  of  new  tissue  having  the  charac- 
teristics I  just  mentioned.  They  grow  commonly  from 
the  pia  mater,  and  both  compress  and  invade  the  sub- 
stance of  the  brain  and  spinal  cord.  They  are  rare 
within  the  substance  of  the  brain,  and  they  are  rare 
also,  although  sometimes  symmetrical,  on  the  cranial 
nerves.  Occasionally  there  is  a  more  diffuse  formation 
of  similar  tissue  in  connection  with  the  dura  mater, 
cerebral  or  spinal. 

Secondly,  there  are  the  growths  in  the  walls  of  the 
arteries,  which  constitute  one  of  the  most  important 
of  these  specific  lesions ;  but  they  also  are  well  known 
and  need  not  detain  us.  One  point,  however,  should 
be  mentioned.  As  generally  met  with  the  disease  is 
recent  and  consists  in  a  thickening  of  the  wall  which 
is  more  limited  than  in  atheroma  and  less  opaque. 
But  when  such  a  disease  has  been  treated,  as  by  a 


AND    THE    NERVOUS    SYSTEM.  19 

course  of  iodide  of  potassium,  the  thickening  is  less 
and  the  opacity  greater,  so  that  the  condition  re- 
sembles more  closely  ordinary  atheroma,  for  which 
it  may  usually  be  mistaken.  I  have  seen  such  dis- 
ease in  one  artery  associated  with  recent  and  character- 
istic changes  in  another.  I  would  ask  you  to  note, 
also,  in  passing,  the  remarkable  correspondence  in  seat 
between  this  arterial  disease  and  ordinary  atheroma. 
Except  in  the  arteries  of  the  brain  and  in  the  aorta, 
syphilitic  disease  is  scarcely  known.  We  ascribe  the 
proclivity  of  those  arteries  to  atheroma  to  the  influ- 
ence of  strain ;  is  this  also  the  cause  that  determines 
their  affection  in  syphilis  ?  I  can  think  of  no  other, 
but  the  fact  must  be  borne  in  mind  in  connection 
with  certain  theories  of  the  origin  of  the  lesions. 

Many  facts  regarding  this  arterial  disease  will  have 
to  be  considered  when  we  come  to  the  diagnostic 
problems  they  furnish,  but  certain  of  its  pathological 
consequences  must  not  be  passed  over.  The  first  is 
the  necrotic  softening  that  follows  occlusion  of  the 
diseased  artery,  or  more  often  that  of  a  branch 
coming  off  from  the  diseased  spot.  It  is  by  this 
necrotic  softening  that  the  disease  most  frequently 
causes  symptoms.  Occlusion,  however,  does  not  always 
lead  to  softening.  Induration  may  result,  especially 
in  the  cortex,  and  more  often  in  children  than  in 
adults.  It  is  no  doubt  due  to  the  arterial  anas- 
tomoses being  sufficient  to  prevent  actual  necrosis, 
although  insufficient  to  maintain  the  integrity  of  the 
tissue. 

A  second  effect  is  the  production  of  aneurism  of  the 


20  LETTSOMIAN   LECTURES    ON   SYPHILIS 

larger  arteries,  thpse  that  are  the  special  seats  of  the 
disease.  Such  aneurisms  seem  to  be  always  due  to 
inflammation  of  the  wall,  by  which  extensible  fibroid 
tissue  is  substituted  for  the  normal  elastic  elements. 
We  know  two  other  causes  of  such  intracranial  aneur- 
isms. One,  very  rare,  is  traumatic  arteritis.  The 
other  is  embolism,  imperfectly  occluding  the  vessel ; 
this  is  probably  the  cause  of  two-thirds  of  such 
aneurisms  before  the  degenerative  period  of  life.  In 
the  remainder,  in  which  there  is  no  history  of  injury 
and  no  evidence  of  embolism,  there  is  a  history  of 
syphilis  in  so  many  cases  as  to  justify  the  opinion 
that  most'of  them  are  due  to  this  influence.  Often  the 
history  is  imperfect,  because  the  aneurism  has  been 
unsuspected  until  the  final  rupture  and  syphilis  has 
not  been  enquired  for.  When  we  consider  how  great 
is  the  amount  of  new  growth  in  the  wall  of  a  diseased 
artery,  and  how  prone  are  the  new  elements  to  change 
into  extensible  fibroid  tissue,  the  wonder  is  that  aneur- 
ism is  not  a  more  frequent  occurrence.  Probably  the 
explanation  is  to  be  found  in  the  common  persistence 
of  the  elastic  layers,  which  afford  the  chief  safeguard 
against  permanent  dilatation.  I  am  only  able  to  offer 
one  additional  instance  of  an  aneurism  due  to  syphilis. 
A  girl,  aged  about  twenty-five,  who  had  suffered  from 
syphilis,  was  admitted  to  University  College  Hospital 
with  the  symptoms  of  a  small  tumor  near  the  crus. 
Soon  after  admission,  she  suddenly  became  uncon- 
scious, and  died  in  a  few  hours.  A  large  amount  of 
blood  was  found  at  the  base  of  the  brain;  it  had 
come  from  a  small  aneurism,  the  size  of  a  large  pea, 


AND   THE   NERVOUS   SYSTEM.  21 

on  the  posterior  cerebral  artery,  near  its  origin.  No 
source  or  evidence  of  embolism  could  be  found. 

A  third,  but  very  rare,  effect  of  syphilitic  vascular 
disease  is  hemorrhage  within  the  substance  of  the 
brain.  Doubtless,  the  reason  why  it  is  so  seldom 
met  with  is  because  the  arteries  within  the  substance 
of  the  brain  are  so  seldom  the  seat  of  syphilitic 
disease.  A  few  cases  have  been  met  with,  and  I  have 
seen  one  remarkable  instance  of  it  in  the  inherited 
malady.  The  patient  was  a  boy,  aged  twelve,  with 
clear  evidence  of  congenital  syphilis.  He  had  suf- 
fered from  some  transient  cerebral  symptoms  at  the 
ago  of  eight.  The  hemorrhage  was  a  large  one;  it 
had  destroyed  the  greater  part  of  one  cerebral  hemi- 
sphere and  had  burst  into  the  ventricles.  Although 
its  source  was  not  discovered,  there  was  such  disease 
as  to  leave  no  doubt  of  its  cause.  Extensive  and 
characteristic  syphilitic  disease  existed  in  the  right 
vertebral  artery,  and  some  smaller  spots  were  seen  on 
the  posterior  cerebrals.  Moreover,  the  aorta  presented 
some  patches  of  similar  disease,  which  was  conspicuous 
also  on  both  coronary  arteries,  near  their  origin  and 
along  their  course,  while  several  raised  yellowish  spots 
existed  on  the  flaps  of  the  mitral  valve.  There  wrere 
no  vegetations,  and  it  should  be  added  that  the  boy 
had  not  had  rheumatic  fever.  The  case  is  thus  re- 
markable for  more  than  one  reason,  not  the  least 
being  the  late  stage  of  the  inherited  disease  at  which 
the  lesion  occured. 

Inflammation  that  is  specific  in  its  pathological  fea- 
tures is  chiefly  meningeal.  The  special  feature  in  this 


22  LETTSOMIAN   LECTURES   ON   SYPHILIS 

also  is  its  hyperplastic  character,  much  new  tissue  being 
produced,  which  may  undergo  the  caseous  or  the  fibroid 
degenerative  change.  Either  of  the  two  membranes 
may  be  inflamed.  In  the  dura  mater  the  inflammation 
is  usually  diffuse,  and  the  tissue  formed  undergoes 
chiefly  the  fibroid  change.  Such  cerebral  pachymen- 
ingitis  is  more  common  in  the  inherited  than  in  the 
acquired  disease.  In  the  pia  mater  the  inflammation 
is  usually  local.  The  new  tissue  may  undergo  the 
characteristic  caseation,  or  fibroid  change  in  it  may 
result  in  the  formation  of  a  layer  of  dense  cicatricial 
tissue,  in  which  nerve  roots  at  the  part  are  in- 
separably involved. 

In  the  spinal  cord  the  most  frequent  chronic  inflam- 
mation is  that  of  the  dura  mater,  the  important  and 
well-known  "  spinal  pachymeningitis."  This  may  dam- 
age greatly  not  only  the  spinal  and  bulbar  nerve  roots, 
but  the  cord  itself,  from  the  great  amount  of  fibrous 
tissue  produced.  The  pia  mater  is  seldom  inflamed 
locally,  and  its  diffuse  inflammation  is  usually  com- 
bined with  that  of  the  dura  mater. 

Inflammation  of  the  substance  of  the  brain  or  cord 
that  can  be  regarded  as  pathologically  specific  is  very 
rare.  Primary  focal  softening  and  induration  have 
been  met  with,  but  most  of  the  cases  are  open  to  the 
question  whether  the  lesion  was  not  due  to  arterial  dis- 
ease. When  these  changes  do  result  from  inflamma- 
tion, they  are  seldom  specific  in  their  characters.  A  case 
of  chronic  disseminated  inflammation  has  been  described 
by  Charcot  and  Gombault,  which  may,  however,  be  re- 
garded as  a  typical  example  of  such  a  specific  inflam- 


AND   THE    NERVOUS   SYSTEM.  23 

mation.  Foci  of  chronic  inflammation  existed  in  the 
brain,  pons,  and  optic  nerves,  and  in  many  of  these  foci 
the  new  tissue  presented  multiple  points  of  caseation, 
although  in  others  it  had  undergone  only  the  fibroid 
change. 

Very  little  is  definitely  known  of  inflammation  of  the 
cranial  nerves  which  is  pathologically  specific.  These 
nerves  are  often  damaged  by  gummata  and  by  chronic 
meningitis,  but  there  is  also  reason  to  believe  that  they 
are  sometimes  the  seat  of  hyperplastic  inflammation, 
involving  the  sheath  and  interstitial  tissue.  The  distri- 
bution is  usually  irregular,  and  it  is  seldom  bilateral.  It 
is  remarkable  that  the  peripheral  parts  of  the  spinal 
nerves  are  very  seldom  affected.  The  discovery  of  the 
susceptibility  of  these  nerves  to  various  toxic  influences 
has  revealed  no  liability  for  them  to  suffer  in  syphilis. 

It  will  be  observed  that  in  speaking  of  specific  path- 
ological characters  I  have  alluded  only  to  those  that 
can  be  recognized  by  the  naked  eye.  I  do  not  think 
that,  at  present,  any  confidence  can  be  placed  on  his- 
tological  characters  only.  Even  the  structure  of  the 
gumma  is  not  distinctive;  all  that  the  microscope  enables 
us  to  say  is  that  the  tumor  may  be  syphilitic.  In  the 
case  of  inflammations,  it  is  very  doubtful  whether  the 
microscopical  characters  have  anything  like  the  signi- 
ficance sometimes  ascribed  to  them  ;  all  the  characters 
need  to  be  considered. 

Are  there  any  lesions  of  the  nervous  system  that  can 
be  said  to  belong  to  the  second  class — lesions  that  pre- 
sent no  pathological  peculiarity — lesions  that  are  due 
to  other  causes  besides  syphilis,  but  which  when  syphi- 


24  LETTSOMIAN   LECTURES   ON   SYPHILIS 

litic  in  origin  have  peculiarities  of  distribution  not 
present  when  they  are  due  to  other  causes  ?  There  are 
a  few  that  may  possibly  be  of  this  character.  One  is  a 
form  of  disseminated  subacute  myelitis,  in  which  de- 
fined islets  of  inflammation  occupy  the  while  substance 
of  the  cord,  chiefly  near  the  surface,  and  are  perhaps 
sometimes  met  with  in  the  brain.  This  form  has  been 
described,  as  related  to  syphilis,  by  Julliard  and  Pierret, 
and  I  have  met  with  one  instance.  Although  syphilis 
seems  to  have  been  its  antecedent  in  the  cases  hitherto 
published,  more  observations  are  needed  before  it  can 
be  regarded  as  a  specific  lesion,  even  when  its  peculiar 
insular  character  is  taken  into  consideration,  and  the 
facts  at  present  do  not  prove  specificity  apart  from  its 
distribution.  The  same  may  be  said  of  a  form  of  multi- 
ple inflammation  of  the  spinal  roots,  regarded  as  a 
specific  by  Kahler,  and  of  certain  forms  of  sclerosis  of 
the  cortex  of  the  brain  (without  arterial  disease)  met 
with  by  Barlow  in  infantile  syphilis. 

It  is  not  likely  that  this  completes  the  series  of  ob- 
viously specific  lesions.  Many  other  morbid  processes 
may  yet  be  added,  by  reason  of  their  characters  or  seat, 
when  our  knowledge  of  them  is  rendered  adequate  by 
a  sufficient  number  of  observations.  For  the  present, 
however,  they  must  be  placed  in  the  class  we  have  now 
to  consider,  the  lesions  of  which  syphilis  is  one  of 
several  possible  causes — lesions  analogous  to  the  appar- 
ently simple  iritis.  The  chief  morbid  processes  which 
seem  to  fall  into  this  class  are  two :  first,  certain  acute 
and  subacute  inflammations ;  and  secondly,  certain 
forms  of  chronic  inflammation  or  focal  sclerosis  of  the 


AND    THE    NERVOUS    SYSTEM.  25 

nerve-centres.  In  the  same  category,  moreover,  we 
must  also  place  the  important  class  of  primary  nerve 
degenerations.  These  we  shall  notice  later,  but  the 
methods  we  are  about  to  consider  are  applicable  to 
them  also. 

The  question  of  evidence  is  of  the  greater  importance 
in  regard  to  this  class  because  we  have  to  proceed  to 
some  extent  without  the  aid  of  pathological  observa- 
tion. We  can  make  the  diagnosis  during  life  with  con- 
siderable confidence  in  some  of  these  cases,  especially 
in  the  acute  inflammations.  In  them,  opportunities 
for  pathological  observation  come  seldom,  and  it  is  very 
doubtful  whether,  when  they  do  come,  they  afford  any 
real  help.  We  have  already  seen  that  it  is  the  new 
tissue  which  gives  to  the  specific  lesions  their  distinctive 
peculiarity.  For  the  formation  of  this  tissue,  time  is 
essential.  In  proportion  as  syphilitic  inflammations 
are  acute,  the  inflammatory  or  congestive  element  pre- 
ponderates, and  the  lesion  assumes  an  apparently  sim- 
ple character.  Obviously,  therefore,  if  an  acute  inflam- 
mation is  produced  by  syphilis,  we  cannot  expect  it  to 
present  such  specific  features  as  would  declare  the 
nature.  We  cannot  expect,  therefore,  that  a  post-mor- 
tem examination  would  decide  the  question ;  and  yet 
we  need,  and  urgently  need,  to  know  whether  such 
lesions  are  or  are  not  among  the  results  of  syphilis. 
But  in  the  case  of  these  apparently  simple  lesions,  only 
two  kinds  of  evidence  seem  at  present  within  our 
reach :  the  first  is  such  sequence  as  proves  causation ; 
the  second  is  the  evidence  of  therapeutics.  It  is  desira- 
ble to  examine  these  two  kinds  of  evidence,  to  inquire 
3 


26  LETTSOMIAN   LECTURES   ON   SYPHILIS 

how  they  can  be  obtained,  and  to  what  limitations  they 
are  subject.  This  inquiry  is  important,  because  cur- 
rent ideas  on  the  subject  seem  ill-defined,  and  yet  we 
have  no  other  evidence.  I  ought,  indeed,  to  recognize 
a  possible  future  source  of  definite  knowledge  most 
part  vague  (at  least  if  we  may  judge  by  their  applica- 
tion), and  also  because,  with  one  exception,  I  do  not 
see  where  else  we  are  to  look  for  evidence. 

The  progress  of  bacteriology  may  supply  us  with  a 
conclusive  criterion.  Such  a  criterion  would  be  avail- 
able also  for  the  specific  lesions,  but  for  them  it  would 
be  merely  confirmatory ;  for  the  lesions  now  under 
consideration  it  would  be  essential.  Unfortunately, 
such  a  criterion  is  still  in  the  dim,  if  not  in  the  distant, 
future.  We  cannot  assume  that  it  will  certainly  follow 
the  discovery  of  the  specific  organism,  or  that  its  appli- 
cation would  be  unlimited.  It  is  not  likely  that  the 
test  would  be  of  negative  as  well  as  positive  signifi- 
cance,— that  the  absence  of  the  organism  would  be  as 
conclusive  as  its  presence.  Thus  even  this  criterion 
may  not  relieve  us  from  the  need  for  other  proof. 

The  evidence  of  sequence  is  thus  of  great  import- 
ance. Regarding  it,  the  first  important  consideration  is 
that  isolated  instances  are  no  proof  of  causation. 
(Let  me  again  remind  you  that  I  am  now  speaking  of 
scientific  proof,  not  of  practical  diagnosis.)  Individual 
sequence  would  be  proof  if  we  could  exclude  all  other 
causes  of  a  disease,  but  this  is,  as  a  rule,  beyond  our 
power.  The  diseases  in  question  have  many  causes, 
and  those  causes  are  imperfectly  known,  so  that  their 
exclusion  in  a  given  case  is  impossible.  The  fact  that 


AND   THE    NERVOUS    SYSTEM.  27 

we  cannot  trace  them  does  not  prove  that  they  do  not 
exist.  We  are  often  unable  to  trace  the  cause  when 
there  is  no  question  of  syphilis,  although  some  ade- 
quate cause  there  must  be.  Hence,  when  there  is 
syphilis,  the  fact  that  we  cannot  trace  any  other  cause 
does  not  justify  us  in  concluding  that  the  disease  in 
question  is  due  to  syphilis.  To  do  so  is  to  treat  the 
unknown  as  non-existent,  and  to  base  our  induction 
not  on  knowledge,  but  on  ignorance.  Consider  how 
many  diseases  coincide  with,  or  succeed,  constitutional 
syphilis,  which  no  one  dreams  of  attributing  to  it.  We 
do  not  ascribe  acute  rheumatism  or  acute  sthenic  pneu- 
monia to  preceding  syphilis,  and  yet,  because  a  morbid 
process  occurs  in  an  organ,  as  the  spinal  cord,  which  is 
sometimes  the  seat  of  syphilitic  processes,  it  is  assumed 
that  the  process  is  due  to  syphilis,  merely  because  the 
patient  is  or  has  been  syphilitic.  It  is  perfectly  certain 
that  such  a  combination  must  often  occur  when  there 
is  no  causation.  It  is  certain,  from  the  mere  law  of 
chance ;  but  such  a  coincident,  without  direct  causation, 
may  well  be  more  frequent  than  mere  chance  will  ex- 
plain. A  general  disease  like  syphilis  may  so  influence 
the  general  health  as  to  predispose  to  many  diseases  for 
which  other  causes  may  exist.  Therefore,  while  indi- 
vidual instances  of  sequence  may  justly  direct  atten- 
tention  to  the  possibility  of  causation — while  they  may 
suggest  a  search  for  other  evidence — they  do  not  prove 
causation.  Indeed,  I  should  not  venture  to  call  your 
attention  thus  specially  to  a  rule  that  is  so  obvious, 
were  it  not  that  medical  literature  abounds  with  cases 


28  LETTSOMIAN    LECTURES    ON    SYPHILIS 

in  which  causation  by  syphilis  is  assumed  to  be  proven 
by  a  single  sequence. 

How,  then,  can  sequence  prove  causation?  How 
can  the  fact  that  a  disease  follows  syphilis  be  evidence 
that  it  is  due  to  syphilis  ?  Only  by  the  strength  of 
numbers.  The  sequence  that  is  without  significance 
when  isolated,  has  the  highest  significance  when  trace- 
able in  a  series  of  cases.  This  fact  is  so  well  known, 
and  the  method  has  been  employed  so  frequently  in 
the  case  of  tabes  and  other  maladies  of  the  same  class, 
that  it  may  seem  needless  to  consider  it  in  detail.  But 
its  use  must  be  widely  extended  if  we  are  to  ascertain 
whether  or  not  many  other  diseases  are  related  to 
syphilis,  and  its  value  depends  largely  on  the  manner 
in  which  it  is  used.  The  number  of  cases  necessary  will 
vary  according  to  the  field  of  observation,  the  frequency 
of  the  disease,  its  incidence  on  age  and  sex,  and  the 
nature  of  the  proof  required.  A  small  number  of  co- 
incidences, in  a  fair  field  of  observation,  might  be  suffi- 
cient to  prove  the  mere  fact  of  causation,  although  a 
much  larger  number  would  be  necessary  to  enable  its 
extent  to  be  estimated.  Used  with  care  the  method  is 
of  the  utmost  value ;  carelessly  employed  it  is  worth- 
less and  merits  the  sneers  that  have  been  so  freely 
bestowed  upon  it. 

It  is  only  practicable  to  approach  the  question  from 
the  side  of  the  disease  to  be  tested,  because  even  those 
diseases  that  are  certainly  consequences  of  syphilis  are 
rare  consequences,  so  that,  from  the  side  of  syphilis,  it 
is  not  easy  to  get  an  adequate  view  of  them.  It  will 


AND   THE   NEKVOUS    SYSTEM.  29 

also  be  convenient,  in  the  case  of  many  diseases,  to 
restrict  the  inquiry  to  the  age  at  which  syphilis  is  com- 
mon and  the  sex  in  which  it  is  most  readily  ascertained. 
If  the  restriction  is  the  same  in  each  series  compared, 
the  validity  of  the  result  is  not  affected.  It  is,  there- 
fore, wise  to  let  the  cases  compared  be  those  of  males 
only,  and  over  twenty -five  years  of  age.  In  some  cases 
it  may  be  well  to  narrow  the  limit  to  cases  between 
twenty-five  and  fifty. 

The  first  task  is  to  ascertain  what  is  the  average  pro- 
portion of  males  over  twenty-five  who  have  suffered 
from  syphilis.  This  term  of  the  comparison  (which 
we  may  term  "  the  standard  ")  will  be  the  same  for 
all  diseases.  It  is  of  great  importance  that  it  should 
be  ascertained,  once  for  all,  from  a  field  sufficiently  ex- 
tensive to  place  the  conclusion  beyond  the  reach  of 
doubt.  Although  one  standard  will  be  sufficient  for 
all  diseases,  it  will  probably  not  be  sufficient  for  all 
classes  or  for  all  places,  since  it  is  probable  that  in  both 
class  and  place  the  frequency  of  syphilis  varies.  It  is 
probably  greater  "in  the  lower  than  in  the  middle  and 
upper  classes,  greater  in  urban  than  in  rural  districts, 
greater  in  seaports  than  in  inland  towns.  Attempts 
have  been  made  abroad  on  a  small  scale  to  ascertain 
the  proportion,  but  not,  I  think,  in  this  country.  I 
regret  that  I  am  able  to  offer  only  a  very  small  contri- 
bution to  it.  I  venture,  however,  to  hope  that  the  need, 
once  pointed  out,  may  not  be  long  unsupplied.  Messrs. 
Raymond-Johnson  and  Marriott  have  kindly  ascer- 
tained the  venereal  history,  positive  and  negative,  of 
112  cases  at  University  College  Hospital,  and  Mr.  Little- 


30  LETTSOMIAN   LECTURES   ON   SYPHILIS 

wood  that  of  200  patients  at  the  Leeds  Infirmary.  The 
result  is  that  in  London  there  is  a  history  of  syphilis 
(including  in  a  few  cases  a  certainly  infecting  sore 
only)  in  10.5  per  cent.,  and  of  a  chancre  of  uncertain 
nature  in  another  10  per  cent.  At  Leeds  the  percent- 
age of  syphilis,  or  hard  chancre,  is  only  6.4,  and  of  a 
chancre  of  uncertain  nature  only  6  per  cent.  This 
shows  very  clearly  the  need  for  more  than  one  stand- 
ard, but  the  want  might  be  supplied  without  much 
difficulty.  A  few  months'  observation  by  the  registrars 
of  all  the  London  hospitals  would  supply  us  with  a 
London  standard,  drawn  from  at  least  five  thousand 
cases,  which  would  be  available  for  all  similar  inquiries 
for  many  years  to  come. 

But  the  figures  I  have  just  mentioned  place  before 
us  at  once  one  of  the  difficulties  of  the  process  of  com- 
parison. It  is  certain  that  some  of  the  patients,  who 
give  a  history  only  of  a  chancre,  have  had  an  in- 
fecting sore — but  how  many?  What  proportion  of 
the  chancre-percentage  should  we  add  to  the  syphilis- 
percentage  to  obtain  the  nearest  approximation  to  the 
truth  ?  Mr.  Berkeley  Hill  and  others,  in  this  country 
and  abroad,  have  published  analyses  which  show  that 
at  least  two-thirds  of  all  venereal  sores  are  infecting. 
We  have,  however,  already  taken  count  of  the  cases  of 
certain  syphilis,  and  of  the  remaining  sores  probably 
the  majority  are  not  infecting.  If  we  add  to  the  per- 
centage of  syphilis  one-quarter  of  the  cases  of  chancre, 
it  will  give  us  about  13  per  cent,  of  syphilis  in  London, 
and  8  per  cent,  at  Leeds. 

The  proportion  among  the  middle  and  upper  classes 


AND   THE   NERVOUS   SYSTEM.  31 

is  probably  less  than  among  the  poor,  and  I  doubt 
whether  it  exceeds  10  per  cent.,  even  in  London.  The 
difficulty  of  ascertaining  it  will  be  much  greater  than 
among  the  poor. 

In  the  other  terms  of  comparison  we  ascertain  in  a 
similar  manner  the  percentage  of  syphilis  among  the 
sufferers  from  the  disease  in  question  corresponding  to 
the  standard  in  sex  and  age.  If  the  proportion  ex- 
ceeds that  of  the  standard,  the  excess  must  be  due 
either  to  the  one  disease  being  a  cause  of  the  other, 
or  to  the  fact  that  both  are  due  to  a  common  cause. 
Obviously,  however,  the  only  conceivable  relation  is 
that  syphilis  is  in  some  way  the  cause  of  the  disease 
in  question.  If  the  excess  is  slight,  and  if  the  interval 
is  short,  indirect  causation  is  possible ;  that  is,  syphilis 
may  have  predisposed  merely  as  any  other  depressing 
disease  may  predispose.  If  the  excess  is  considerable, 
we  must  assume  direct  causation. 

But  the  comparison  itself  is  not  quite  a  simple 
matter.  The  significant  fact  is  the  excess  of  the 
syphilitics  among  those  who  suffer  from  the  disease, 
and  we  have  to  ascertain  this  excess.  It  may  seem 
sufficient  to  deduct  the  percentage  in  the  standard 
from  the  percentage  in  the  disease,  and  to  consider 
the  difference  as  the  percentage  of  causation.  But 
this  would  be  erroneous,  as  an  example  will  show. 
Let  us  assume,  taking  simple  numbers  for  con- 
venience, that  the  percentage  of  syphilis  in  the 
standard  is  10,  and  in  the  disease  50.  It  is  not  right 
simply  to  deduct  10  from  50,  and  assume  40  per 
cent,  causation.  We  start  with  100  cases,  and  if  we 


32  LETTSOMIAN   LECTURES   ON   SYPHILIS 

thus  assume  40  to  be  the  proportion  of  causation,  we 
have  left  10  cases  of  accidental  coincidence  and  50 
without  syphilis.  Thus  we  assume  that  in  10  cases 
out  of  60  there  is  mere  coincidence,  whereas  our 
assumed  standard  shows  that  in  60  persons  there  will 
be  only  6  with  merely  coincident  syphilis.  The  true 
method,  I  take  it,  may  be  expressed  in  the  following 
rule :  Deduct  from  the  syphilitics  the  number  that 
bears  the  same  proportion  to  the  non-syphilitics  as  is 
found  in  the  standard ;  the  residue  will  represent  the 
causation.  Thus  in  our  example  we  must  deduct 
from  the  50  syphilitics  not  10,  but  5.5,  because  not 
10  but  5.5  bears  the  same  proportion  to  50  as  10 
does  to  90  (10  in  100),  and  the  proportion  in  which 
there  is  causation  will  not  be  40,  but  44.5.  It  is 
certain  that  such  a  deduction  for  mere  coincidence 
is  necessary  in  the  case  of  diseases  that  are  often  due 
to  other  causes,  although  it  is  open  to  consideration 
whether  this  deduction  is  justified  in  the  case  of  dis- 
eases of  which  syphilis  is  the  chief  cause.  But  its 
amount  lessens  in  inverse  ratio  to  the  proportion  in 
which  syphilis  can  be  traced,  and  when  this  propor- 
tion is  high,  the  deduction  becomes  so  small  as  to 
be  unimportant.  If,  for  instance,  syphilis  can  be 
traced  in  80  per  cent,  of  the  cases,  the  deduction  for 
coincidence  would  be  less  than  3  per  cent.  The  error 
from  neglecting  it  will  then  be  scarcely  appreciable, 
especially  in  the  face  of  the  graver  source  of  un- 
certainty we  have  next  to  consider. 

Whatever  proportion  of  syphilis  is  found  will  fall 
short  of  the  truth.     This  is  certain  from  the  fact  that 


AND    THE    NEKVOUS   SYSTEM.  33 

persons  occasionally  suffer  from  syphilis  and  do  not 
know  it,  or  know  it  only  with  a  knowledge  which 
soon  passes  from  their  memory.  Many  persons  who  pre- 
sent unequivocal  signs  of  old  syphilis  can  give  a  history 
only  of  a  chancre,  and  others  not  even  of  this.  We 
meet  with  persons  who  know  of  no  sore,  who  give 
no  history  of  syphilis,  and  yet  have  had  the  disease. 
This  fact  is  well  known,  but  it  is  so  important  that  I 
venture  to  emphasize  it  with  a  few  instances.  A  gen- 
tleman had  once,  and  only  once,  a  slight  sore.  He 
showed  it  to  a  doctor,  who  said  it  was  of  no  importance, 
and  touched  it  with  caustic.  In  a  few  days  it  was  well, 
and  was  soon  almost  forgotten,  for  no  after-symptoms 
occurred  to  keep  it  in  mind.  In  a  year  or  so  he  married 
a  lady  in  his  own  station:  She  bore  him  two  dead  chil- 
dren, and  then  a  living  one.  The  latter  soon  showed 
signs  of  syphilis,  and  became  paralyzed  and  imbecile. 
Then  the  wife  herself  died  from  the  effects  of  the  same 
disease.  Similar  cases,  we  may  hope  less  tragic,  must 
be  known  to  all  of  you — cases  in  which  the  transmis- 
sion of  the  disease  to  others  is  the  first  proof  of  its 
existence.  A  striking  instance  is  the  first  case  of  pro- 
gressive ophthalmoplegia  in  which  the  nature  of  the 
lesion  was  proved.  I  suppose  there  is  no  one  more 
skilled  jn  tracing  syphilis  than  Mr.  Jonathan  Hutchin- 
son,  and  yet  in  this  case  the  search,  many  times  renewed, 
failed  to  reveal  any  indication  of  the  disease ;  there  was 
not  even  a  venereal  sore  to  suggest  it ;  but  after  the 
man's  death  a  child  of  his  was  brought  to  Mr.  Hut- 
chinson  with  interstitial  keratitis  and  notched  teeth.  I 
have  met  with  many  patients  who  had  signs  of  the  past 
4 


34  LETTSOMIAN   LECTURES   ON   SYPHILIS 

disease,  in  some  indubitable  lesion  of  eye,  tongue,  throat, 
or  skin,  who  could  give  no  history  of  a  chancre.  But 
I  am  able  to  offer  you  more  definite  facts,  for  which  I 
am  indebted  to  my  friend  Dr.  RadclifTe  Croker.  He 
has  been  kind  enough  to  ascertain  from  his  case-records 
at  University  College  Hospital  the  proportion  of  cases 
of  tertiary  syphilitic  skin  eruptions  in  which  there  was 
no  history  of  a  chancre.  He  has  found  56  cases  of  such 
eruptions,  cases  that  are  consecutive  and  unselected, 
and  in  no  less  than  11  of  these  the  occurrence  of  any 
chancre  was  unknown.  This  is  a  proportion  of  20  per 
cent.  It  cannot  be  doubted,  moreover,  that  besides 
such  cases  there  must  be  many  more  who  have  no  late 
symptoms  whatever  to  reveal  the  disease. 

These  facts  suggest  a  question  most  important  in 
regard  to  the  problem  we  are  considering,  the  actual 
frequency  of  what  may  be  termed  latent  syphilis,  in 
which  the  manifestations  of  the  disease  are  insignifi- 
cant, and  are  either  unnoticed  or  untreated,  so  that, 
years  afterward,  the  memory  of  them  is  reduced  to  a 
vanishing-point  in  the  vista  of  the  past.  May  not  such 
cases  be  far  more  frequent  than  is  generally  thought — 
more  frequent,  indeed,  than  we  can  ascertain  ?  Besides 
the  facts  I  have  mentioned  there  are  others  which,  if 
they  do  not  suggest  this  conclusion,  at  least  harmonize 
with  it  and  are  explained  by  it.  Many  observers  have 
noticed  how  often  severe  late  lesions  have  followed  an 
early  stage  that  was  slight  or  unnoticed.  It  has,  indeed, 
more  than  once  been  suggested  that  there  is  an  actual 
alternation  in  severity  between  the  early  and  the  late 
effects.  Such  an  alternation  would  explain  the  facts, 


AND   THE    NERVOUS   SYSTEM.  35 

but  cases  are  frequent  enough  in  which  both  stages  are 
alike  severe.  May  not  the  frequent  apparent  alternation 
be  simply  due  to  the  great  frequency  of  mild  or  latent 
syphilis?  Take,  again,  the  fact  epitomized  in  what  is 
termed  (abroad  more  often  than  in  England)  Colles's  Law 
— the  fact  that  a  woman  who  bears  a  syphilitic  child, 
although  apparently  free,  is  proof  against  infection,  and 
must  therefore  have  suffered.  It  is  supposed  that  preg- 
nancy is  in  some  way  antagonistic  to  the  activity  of  the 
disease,  but  such  antagonism  is  certainly  often  not 
evident,  and  the  anomaly  may  be  equally  explained 
by  the  frequency  of  latent  syphilis. 

It  is  therefore  certain  that  the  facts  we  can  ascertain 
will  fall  short  of  the  real  facts,  and  will  fall  short  of 
them  by  a  quantity  which,  because  it  is  unknown,  must 
not  therefore  be  neglected.  Whatever  the  actual  amount 
of  the  discrepancy,  its  influence  will  be  the  greater  the 
larger  the  number  of  cases  in  which  syphilis  can  be 
traced.  For  instance,  to  take  what  may  or  may  not  be 
an  extreme  proportion,  let  us  suppose  that  syphilis  can- 
not be  ascertained  in  one  quarter  of  the  patients  who 
have  suffered  from  it — that,  besides  the  cases  in  which 
there  is  clear  evidence  of  the  disease,  there  are  one- 
third  more,  on  an  average,  in  whom  we  cannot  ascertain 
it  after  the  lapse  of  years.  This  would  raise  the  pro- 
portion of  syphilitics  among  adult  males  to  about  18  per 
cent.,  but  it  would  raise  a  proportion  of  50  per  cent,  to 
70,  and  of  60  per  cent,  to  80.  To  ascertain  the  mere 
fact  of  causation  we  may  indeed  neglect  the  discrepancy, 
but  we  must  recognize,  at  least  its  existence,  when  we 
endeavor  to  estimate  the  extent  of  causation. 


36  LETTSOMIAN   LECTURES    ON   SYPHILIS 

One  last  general  remark.  For  the  comparisons  to  be 
significant  the  facts  must,  as  a  rule,  be  specially  ob- 
served. It  is  one  of  the  many  lessons  of  scientific 
history,  in  no  part  more  conspicuous  than  in  medicine, 
that  facts  observed  without  special  reference  to  the 
question  at  issue  are  of  very  little  value  for  its  decision. 

On  the  second  kind  of  evidence,  that  of  therapeutics 
— the  influence  of  drugs  on  the  disease — I  must,  and 
can,  be  more  brief.  The  considerations  are  not  less  im- 
portant, but  they  are  familiar,  at  any  rate  in  the 
abstract,  and  we  shall  have  occasion  to  return  to  them 
in  discussing  the  problems  of  diagnosis.  Unfortunately 
the  limitations  to  the  use  of  this  method  are  such  as 
to  reduce  very  much  its  scientific  value. 

The  chief  conditions  that  must  be  secured  may  be 
thus  enumerated :  (1)  The  effect  of  the  drug  must  be 
decided  and  unequivocal.  (2)  Its  influence  must  not 
be  obscured  by  any  other  change  in  the  measures  em- 
ployed, which  might  cause  the  improvement  observed. 
(3)  The  lesion  must  not  be  one  of  which  the  symptoms 
tend  to  spontaneous  subsidence.  (4)  The  lesion  must 
not  be  one  that  can  be  influenced  by  the  drug,  when  it 
is  not  due  to  syphilis.  (5)  Before  a  negative  result  can 
be  admitted  as  evidence  that  the  lesion  is  not  due  to 
syphilis,  we  must  be  satisfied  that  the  damage  produced 
is  not  so  great  that  its  manifestations  cannot  speedily 
subside.  These  conditions  render  the  process  almost 
useless  for  our  present  object.  The  method  is  applica- 
ble chiefly  to  chronic  lesions,  in  which  the  influence  of 
treatment  can  be  clear  and  decided.  Acute  lesions,  if 


AND    THE    NERVOUS    SYSTEM.  37 

they  are  slight,  have  too  great  tendency  to  subside,  and, 
if  they  are  severe,  have  effects  of  too  prolonged  dura- 
tion. 

We  may  briefly  glance  at  the  lesions  to  which  these 
methods  of  proof  apply.  First,  there  are  two  import- 
ant acute  inflammations — those  of  the  membranes  of 
the  brain  and  of  the  substance  of  the  spinal  cord. 
Are  these  ever  due  to  syphilis  ?  Unfortunately,  I  can 
only  ask  the  question,  and  try  to  show  how  to  obtain 
the  answer,  which  I  am  not  able  to  give.  That 
syphilis  causes  chronic  meningitis  is  one  of  the  surest 
facts  of  medicine.  It  causes  chronic  inflammation  of 
the  membranes  of  the  brain  and  of  the  spinal  cord, 
and  either  may  be  diffuse  or  focal.  The  latter  is  usually 
in  the  pia  mater,  and  is  associated  with  the  formation 
of  caseating  new  tissue.  In  the  cord  it  usually  begins 
at  the  surface  and  involves  the  nerve  roots,  so  as  to  give 
rise  to  obtrusive  radiating  pains,  or  muscular  wasting. 
The  diffuse  inflammation  more  often  involves  the  dura 
mater  and  is  attended  with  the  production  of  fibrous 
tissue  constituting  in  the  cord  what  has  been  called 
"  hypertrophic  pachymeningitis,"  which  compresses 
the  cord  itself  and  gives  rise  to  grave  symptoms. 
Within  the  skull  bilateral  headache  and  general  con- 
vulsions may  be  its  expression,  whereas  the  focal 
inflammation  gives  rise  to  fits  that  begin  locally. 
These  facts  are  very  important  in  respect  to  diagnosis. 
Whether  syphilis  also  causes  acute  meningitis,  such  as 
reaches  a  considerable  degree  of  intensity  in  a  few  days, 
is  still  uncertain.  Analogy  suggests  that  an  acute 
meningitis,  like  an  acute  iritis,  may  be  due  to  it, 


38  LETTSOMIAN    LECTURES   ON   SYPHILIS 

but  this  is  enough  only  to  make  us  search  for  evidence. 
Morbid  anatomy,  as  we  have  seen,  is  not  likely  to  sup- 
ply an  answer.  The  therapeutic  test  is  of  little  value, 
on  account  of  its  essential  limitations,  for  we  dare  not 
secure  the  absence  of  other  influences ;  we  are  bound  to 
do  all  we  can  for  the  safety  of  the  patient,  and  there  is 
reason  to  believe  that  mercury  may  determine  the  sub- 
sidence of  an  inflammation  that  is  not  syphilitic.  I 
have  once  known  the  symptoms  of  a  general  menin- 
gitis to  develop  most  acutely  in  a  man  who  had  suffered 
from  syphilis,  and  then  to  slowly  pass  away  under  the 
influence  of  mercury  ;  but  such  a  case  can  alone  do  no 
more  than  raise  or  strengthen  a  suspicion ;  it  cannot 
supply  the  needed  proof.  Acute  meningitis  is  very 
rare  in  adult  men,  but  it  does  occur  when  we  can 
exclude  syphilis,  and  hence  the  question  of  causa- 
tion can  be  decided  only  by  a  series  of  cases.  The 
readiness  with  which  acute  meningitis  is  ascribed  to 
syphilis  by  some  writers  is  astonishing,  or  would  be 
astonishing  had  not  the  capacity  for  wonder  been 
already  diminished  by  the  process  of  the  diagnosis  of 
the  disease.  To  quote  one  instance :  A  "patient 
suffered,  for  a  few  days  only,  from  pain  in  one  temple, 
an  elevation  of  temperature  of  half  a  degree  Fahrenheit, 
and  diminished  frequency  of  the  pulse.  This  was  con- 
sidered to  justify  the  diagnosis,  not  indeed  of  menin- 
gitis, but  of  a  lesion  safe  in  the  region  of  hypothesis, 
local  congestion  of  the  membranes.  This  assumed 
lesion  was  further  ascribed  to  syphilis,  because  the 
symptoms  occurred  twenty-five  days  after — not  definite 
constitutional  symptoms,  not  even  after  enlargement  of 


AND    THE    NERVOUS    SYSTEM.  39 

the  glands,  not  even  after  the  primary  induration  was 
discovered,  but  twenty-five  days  after  the  exposure  to 
infection  !  We  scarcely  marvel  after  this  to  find  that  the 
case  is  regarded  as  affording  strong  support  to  a  theory 
— indeed,  as  part  of  its  proof — that  the  early  symp- 
toms of  syphilis  frequently  include  congestive  lesions  of 
internal  organs,  especially  of  the  nerve  centres,  which 
are  analogous  to  the  early  eruptions  on  the  skin.  I 
think  our  time  may  be  better  occupied  than  by  dis- 
cussing this  theory  in  detail. 

The  possible  relation  of  myelitis  to  syphilis  is  one  of 
the  most  difficult  problems  connected  with  this  subject, 
and  it  is  one  on  which  definite  evidence  is  specially 
needed.  The  term  "myelitis,"  even  in  its  narrower 
sense,  includes  diseases  widely  different  in  their  nature 
and  pathological  relations,  and  these  relations  are  still 
imperfectly  known.  We  can,  however,  distinguish 
acute  transverse  myelitis,  sub-acute  disseminated  my- 
elitis, and  acute  poliomyelitis,  as  fairly  well-defined 
forms,  which  have  distinctly  different  causation,  and 
the  relation  of  each  to  syphilis  must  be  separately 
ascertained.  In  each  form  this  investigation  has  still 
to  be  made.  The  fact  that  special  observations  are 
necessary  renders  it  difficult  for  the  evidence  to  be  ob- 
tained by  any  one  person.  It  is  certain  that  not  one 
of  these  forms  is  exclusively  related  to  syphilis,  and 
it  is  not  probable  that  the  relation  is,  in  any  one  of  them, 
so  preponderant  that  the  fact  could  be  decided  by  a 
small  number  of  observations,  for  we  must  depend 
almost  entirely  on  the  evidence  of  sequence.  The 
limitations  to  the  method  of  therapeutics  are  here  pro- 


40  LETTSOMIAN   LECTURES    ON   SYPHILIS 

hibitory.  The  course  of  the  symptoms  is  no  more  guide 
to  that  of  the  inflammatory  process  than  is  the  course 
of  a  cardiac  murmur  evidence  of  the  course  of  the  en- 
docarditis to  which  it  was  due.  If  the  inflammation 
of  the  spinal  cord  is  trifling,  the  tendency  to  sponta- 
neous improvement  deprives  the  subsidence  of  the 
symptoms  of  any  significance.  Moreover,  there  are 
some  facts  that  suggest  that  the  less  acute  forms  may 
be  due  to  syphilis,  and  yet  may  not  yield  to  its  treat- 
ment. In  the  case  of  an  inflammation  such  a  state- 
ment seems  self-contradictory,  but  in  dealing  witli  facts 
we  must  lay  aside  all  our  preconceptions.  I  mentioned 
just  now  a  form  of  insular  myelitis,  possibly  always 
syphilitic  in  origin  and  specific  in  its  distribution. 
(To  avoid  confusion  I  may  point  out  that  in  this  form 
the  inflammation  is  in  small  islets;  in  the  common 
form  of  disseminated  inflammation  larger  scattered 
tracts  or  areas  are  affected.)  If  the  insular  myelitis  is 
syphilitic,  it  does  not  seem  to  be  distinctly  amenable  to 
treatment.  In  the  cases  hitherto  observed  the  patients 
have  died.  In  some  of  them,  as  in  my  own,  anti- 
syphilitic  treatment  had  no  influence  on  the  disease. 

I  have  seen  several  other  cases  of  sub-acute  and  sub- 
chronic  myelitis  in  syphilitic  subjects,  in  which  neither 
iodide  in  large  doses,  nor  mercury  pushed  to  salivation 
had  any  appreciable  influence  on  the  lesion,  either  on 
its  extension  in  the  cord  or  its  intensification  in  the 
parts  first  affected.  This  seems  also  to  have  been  true 
of  the  remarkable  case  of  chronic  caseating  inflamma- 
tion described  by  Charcot  and  Gombault,  to  which  I 
have  already  alluded  as  a  lesion  pathologically  specific. 


AND    THE    NERVOUS    SYSTEM.  41 

Here,  then,  we  are  driven  back  on  sequence  for  our 
evidence  of  causation,  and  the  needful  observations, 
serial  and  unselected,  have  yet  to  be  made.  The  same 
statement  must  be  made  regarding  transverse  myelitis, 
the  most  common  variety,  recognizable  during  life 
without  much  difficulty.  My  own  experience  is  sug- 
gestive only.  I  have  seen  several  cases  in  which  the 
disease  followed  syphilis,  more,  I  think,  than  mere 
coincidence  will  explain.  On  the  other  hand,  I  have 
met  with  no  cases  of  acute  poliomyelitis  suggesting  a 
syphilitic  causation,  and  the  significance  of  a  few  cases 
that  have  been  published  as  evidence  of  such  causation 
seems  to  me  open  to  doubt.  We  must  remember  that 
the  sub-acute  form  has  only  lately  been  distinguished 
from  peripheral  neuritis,  and  the  most  common  cause 
of  peripheral  neuritis,  alcoholism,  is  sometimes  associ- 
ated with  syphilis  as  a  consequence  of  mode  of  life. 

Another  acute  affection  of  the  spinal  cord,  the 
mysterious  acute  ascending  paralysis,  has  also  been 
supposed  to  be  a  result  of  syphilis,  partly  on  the 
ground  of  sequence,  partly  on  that  of  recovery  under 
the  influence  of  mercury.  The  proportion  of  pub- 
lished cases  in  syphilitic  subjects  is  certainly  large,  and 
justifies  careful  investigation.  In  considering  the  in- 
fluence of  mercury  we  must  remember  that  there  is 
some  evidence  that  other  acute  toxic  states  besides  that 
of  syphilis  are  modified  by  mercury.  In  the  course  of 
some  investigations  made  in  1885,  at  the  Brown  Insti- 
tution, Dr.  Cash  discovered  that  animals,  brought 
under  the  influence  of  mercury,  resist  otherwise  fatal 
inoculation  with  the  anthrax  bacilli — a  remarkable 


42  LETTSOMIAN    LECTURES   ON    SYPHILIS 

fact,  which  does  not  seem  to  have  attracted  the  atten- 
tion it  deserves.  We  must  also  remember  that  the 
syphilitic  organisms  may  leave  behind  them  a  product 
of  a  different  nature  which  may  not  be  amenable  to 
the  influences  which  affect  the  organisms  themselves.. 

Regarding  the  focal  sclerosis  of  the  nerve  centres, 
including  what  may  be  termed  "  chronic  sclerotic  in- 
flammation," I  have  little  to  say.  The  evidence  seems 
to  be  against  any  relation  to  syphilis  of  true  insular 
sclerosis.  Only  future  observations,  for  which  we  may 
have  long  to  wait,  can  determine  the  question  as 
regards  certain  other  extremely  rare  forms  of  diffuse 
sclerosis.  A  remarkable  case  of  miliary  degeneration 
of  the  gray  matter  of  the  brain,  published  by  me  some 
years  ago,  occurred  in  a  syphilitic  subject.  Many  years 
ago  I  examined  for  Dr.  Hughlings  Jackson  a  brain  of 
an  old  syphilitic,  which  presented  a  remarkable  indura- 
tion of  a  large  part  of  the  white  substance  of  one  hemi- 
sphere, without  change  in  tint.  (The  history  of  this 
case,  unfortunately,  we  have  been  unable  to  trace.) 
Lastly,  sclerosis  of  the  cortex  in  infantile  syphilis,  as 
we  have  already  seen,  may  possibly  be  sometimes  prim- 
ary, although'  generally  it  is  the  result  of  inflammation 
in  infarcted  areas. 

The  processes  we  have  hitherto  considered  originate 
either  outside  the  nerve  centres  themselves,  or,  when 
within  the  nerve  tissue,  are  essentially  interstitial.  Of 
all,  therefore,  it  seems  to  be  true  that  the  primary  mor- 
bid process  is  independent  of  the  nerve  elements 
themselves.  These  elements  suffer  just  as  they  would 
from  any  similar  process,  not  syphilitic  in  nature.  It 


AND    THE    NERVOUS    SYSTEM.  43 

is  on  these  simple  processes  in  the  nerve  elements,  and 
on  these  only,  that  most  of  the  symptoms  depend — a 
fact  of  the  utmost  practical  importance. 

The  spinal  nerves  seem  to  escape  the  influence  of 
syphilis,  and  the  cranial  nerves  suffer  chiefly  at  the 
base  of  the  brain,  where  several  are  involved  in  a  focus 
of  inflammation.  To  this  some  of  the  nerves  to  the 
eyeball  seem  to  offer  an  exception ;  they  may  suffer 
alone.  The  facial  nerves  present  a  remarkable  free- 
dom. The  nerves  that  arise  from  the  side  of  the 
medulla  are  often  involved,  especially  the  hypoglossal 
and  spinal  accessory,  causing  palsy  of  the  tongue, 
palate,  and  vocal  cord,  on  one  side.  These  palsies  are 
seldom  due  to  any  other  cause,  so  that  their  occurrence 
should  suggest  syphilis  at  once  to  your  mind. 

Paralysis  in  the  arm,  due  to  deep  cellulitis  in  the 
neck,  chronic  and  indurating,  is  another  occasional 
result.  Note,  however,  that,  as  a  rule,  the  spinal  nerves, 
if  they  suffer,  do  so  only  on  one  side  and  in  conse- 
quence of  damage  to  their  roots. 

Until  lately  it  was  believed  that  the  influence  of 
syphilis  was  limited  to  the  production  of  such  lesions 
as  we  have  hitherto  considered.  But  modern  observa- 
tions, led  by  those  of  Fournier,  have  resulted  in  a  con- 
siderable amount  of  evidence  that  the  effects  of  syphilis 
are  not  thus  limited — that  the  disease  is  followed  by 
lesions  of  a  totally  different  nature,  and  is  followed  by 
them  in  a  way  that  admits  of  no  other  explanation 
than  that  it  causes  them.  These  lesions  are  degenera- 
tions of  the  nerve  structures,  with  such  a  distribution 
according  to  function  as  can  be  explained  only  by 


44  LETTSOMIAN   LECTURES   ON   SYPHIIIS 

assuming  that  the  process  begins  in  the  nerve  elements 
themselves.  The  relation  of  these  "  system  degenera- 
tions "  to  syphilis  was  first  asserted  in  the  case  of  tabes, 
locomotor  ataxy,  and  this  disease  is  still  the  most  con- 
spicuous example,  around  which  most  of  the  contro- 
versy has  turned.  The  assertion  that  syphilis  causes 
lesions  so  totally  unlike  the  known  effects  of  the  dis- 
ease was  sufficiently  startling  to  be  received  with  sur- 
prise and  suspicion,  a  suspicion  not  lessened  by  the  fact 
that  the  only  evidence  of  the  relation  was,  and  still  is, 
that  which  depends  on  numbers  for  its  weight.  Various 
objections  were  urged.  It  was  said  that  syphilis  could 
not  cause  such  disease ;  that  cases  of  true  syphilitic 
lesions  had  been  mistaken  for  degenerations ;  and  that 
if  tabes  were  due  to  syphilis  the  lesion  must  be  pri- 
marily interstitial,  and  not  a  primary  nerve-degenera- 
tion. The  common  absence  of  benefit  from  anti-luetic 
treatment  was  urged  in  support  of  the  objection,  and 
the  statistical  evidence  was  met  by  other  figures  of 
different  significance,  obtained  from  existing  records. 
Some  of  these  arguments,  however,  were  seen  to  be 
untenable  as  soon  as  they  wrere  clearly  stated.  The 
assertion  that  syphilis  could  not  cause  a  lesion  different 
in  nature  from  the  effects  previously  known,  was  too 
obviously  a  transfer  to  medicine  of  the  method  em- 
ployed by  Canute  upon  the  sea-shore.  The  absence  of 
evidence  of  one  kind,  that  of  therapeutics,  was  mani- 
festly no  refutation  of  a  totally  different  species  of 
proof.  The  comparison  of  statistics,  moreover,  resulted 
in  a  curious  and  instructive  episode  in  the  history  of 
medicine.  When  those  observers  who  had  gathered 


AND   THE   NERVOUS   SYSTEM.  45 

their  cases  from  old  records  came  to  make  fresh  obser- 
vations on  the  subject,  they  found  that  the  two  sets  did 
not  correspond.  They  found  that  the  proportion  of 
syphilis  yielded  by  the  special  observations  was  much 
higher,  and  in  more  than  one  instance  the  special  in- 
quiry transformed  an  opponent  into  a  supporter  of  the 
new  opinion.  It  was  one  more  instance  of  the  fact  I 
just  now  mentioned — the  uselessness  of  figures  based 
on  observations  not  made  with  the  special  question  in 
view.  . 

The  proportion  of  cases  of  tabes  in  which  syphilis 
has  been  traced  by  different  investigators  has  varied 
much — from  90  per  cent,  down  to  a  proportion  that  has 
been  held  to  be  not  far  above  the  range  of  accidental 
association.  Instead  of  detailing  to  you  the  various 
statements  that  have  been  made,  it  may  be  more  in- 
structive to  give  the  figures  supplied  by  a  consecutive 
and  unselected  series  of  cases  that  has  come  under  my 
own  observation.  Of  170  cases  of  characteristic  tabes 
in  males  there  was  evidence  of  syphilis  (in  a  few  con- 
fined to  a  chancre  certainly  hard)  in  55  per  cent.  In 
another  14  per  cent,  there  was  a  history  of  a  sore  only, 
of  unknown  nature.  In  only  31  per  cent,  could  neither 
be  ascertained.  Of  the  170,  92  were  seen  in  private, 
and  78  were  hospital  patients.  The  percentage  of 
syphilis  in  private  cases  was  57,  in  the  hospital  patients 
52.  Probably  the  difference  is  due  to  the  more  accu- 
rate information  to  be  obtained  from  those  who  are 
most  likely  to  notice  and  remember  such  diseases.  It 
is  remarkable,  however,  that  the  proportion  between 
the  cases  of  syphilis  and  the  cases  without  even  a 


46  LETTSOMIAN    LECTUKES   ON   SYPHILIS 

chancre  is  exactly  the  same  in  the  two  sets,  as  11  to  6. 
The  difference  in  the  percentage  arises  from  the  fact 
that  a  history  of  a  sore  of  unknown  nature  was  almost 
twice  as  frequent  among  the  hospital  as  among  the 
private  patients.  In  either  series  the  addition  to  the 
syphilitics  of  one  quarter  of  the  cases  of  chancre  will 
give  about  60  per  cent.,  and  a  deduction  for  mere  acci- 
dental coincidence  would  have  at  least  55  per  cent,  of 
unquestionable  causation.  But  it  is  certain  that  to  this 
a  large  addition  must  be  made  for  untraceable  syphilis. 
These  figures  are  obtained  by  placing  all  doubtful  cases 
on  the  negative  side,  including  many  with  a  strong 
presumption  of  syphilis.  If  it  is  true  that  latent  syphi- 
lis is  common,  and  if  the  disease  can  be  proved  to  be  a 
cause  of  tabes  in  more  than  half  the  cases,  is  it  not 
almost  certain  that  a  large  proportion  of  the  remainder 
are  really  due  to  it?  In  most  of  them  no  other  cause 
could  be  traced,  and  in  not  more  than  5  per  cent,  of 
the  whole  had  there  been  no  exposure  to  the  risk  of 
infection.  Although  the  method  which  discloses  syphi- 
lis in  an  exceedingly  large  proportion  of  the  cases  may 
be  open  to  question,  I  cannot  but  think  that  the  ob- 
servers who  describe  it  in  75  or  80  per  cent,  are  not  far 
from  the  real  truth. 

Not  only  is  the  relation  of  syphilis  to  tabes  beyond 
reasonable  doubt,  but  we  are  beginning  to  discern  that 
there  are  other  diseases  that  stand  in  a  similar, 
although  unequal,  relation  to  the  disease.  One  other 
group  of  degenerations  we  can,  indeed,  connect  with 
syphilis  as  surely  and  as  extensively  as  tabes — the  de- 
generative ocular  palsies,  which,  often  associated  with 


AND   THE    NERVOUS   SYSTEM.  47 

tabes,  occur  also  alone.  There  is  strong  evidence  of  a 
similar  relation  in  simple  atrophy  of  the  optic  nerve. 
Among  the  motor  palsies,  one  of  the  most  important  to 
the  physician,  although  the  least  important  to  the  pa- 
tient, is  the  isolated  loss  of  the  light-reflex  of  the  iris, 
with  which  the  name  of  Argyll-Robertson  is  connected. 
I  have  notes  of  only  twenty-two  cases  in  which  this 
symptom  existed  apart  from  other  degenerative  affec- 
tions of  the  nervous  system,  but  I  believe  that  it  is 
much  less  rare  than  this  number  might  suggest.  It  is 
seldom  looked  for,  unless  other  symptoms  suggest  de- 
generative disease.  Of  these  twenty-two  cases,  syphilis 
was  certain  in  twelve,  and  highly  probable  in  three 
others,  while  two  more  had  a  history  of  a  venereal  sore. 
In  six  cases  there  was  no  history  or  evidence  of  either 
syphilis  or  a  chancre ;  nevertheless,  two  of  them  had 
had  an  attack  of  sudden  hemiplegia  in  early  adult  life, 
without  any  indication  of  a  cause  of  embolism — an 
event  that  always  affords  ground  for  suspecting  syphilis. 
From  these  facts  we  may  feel  confident  that  syphilis 
existed  in  two-thirds  of  the  cases.,  and  we  may  suspect 
that  it  existed  in  three-quarters.  One  of  the  cases  was 
a  young  girl,  the  subject  of  inherited  syphilis,  and 
another  case  was  this  girl's  mother. 

The  relation  of  this  symptom  to  syphilis  makes  it 
one  of  great  practical  value.  It  proves  that  a  degener- 
ative process  is  at  work  in  the  nervous  system,  and  it 
raises  a  strong  presumption  that  this  process  is  the  re- 
sult of  syphilis.  It  is  true,  the  dependence  on  central 
degeneration  has  not  been  proved  by  observation,  but 
the  indirect  evidence  of  it  is  very  strong. 


48  LETTSOMIAN    LECTURES   ON    SYPHILIS 

The  more  extensive  palsies,  external  and  internal,  to 
which  the  term  "  ophthalmoplegia  "  has  been  applied  are 
much  more  rare.  They  occur  in  syphilitic  subjects  in  as- 
sociation with  tabes,  and  also  alone,  as  was  clearly  proved 
by  Mr.  Jonathan  Hutchinson.  In  the  case  of  external 
ophthalmoplegia,  in  which  I  made  an  examination  of 
the  nerve  centres,  preceding  syphilis  was  certain  (the 
evidence  I  have  already  mentioned),  and  the  lesion  was 
as  pure  a  nerve-degeneration  as  can  be  conceived.  But 
these  diseases,  like  tabes,  are  not  exclusively  related  to 
syphilis ;  they  certainly  occur,  now  and  then,  in  persons 
in  whom  syphilis  can  be  excluded. 

This  evidence  seems  to  leave  no  room  for  doubt.  It 
receives,  moreover,  a  strong  emphasis  from  the  remark- 
able fact  that  nerve-degenerations  such  as  succeed  ac- 
quired syphilis  in  the  adult,  are  met  with  also  in  young 
persons  who  are  the  subjects  of  the  inherited  disease. 
Such  cases,  it  is  true,  are  rare,  but  their  rarity  may  be 
due,  less  to  any  difference  in  the  influence  of  the  disease, 
than  to  the  greater  vital  stability  possessed  by  younger 
tissues.  I  have  met  with  several  examples,  and  their 
interest  may  justify  a  brief  mention  of  some.  One  case 
was  a  lad  who,  in  infancy  and  early  childhood,  suffered 
much  from  various  manifestations  of  syphilis,  includ- 
ing slight  hemiplegia  and  choroiditis.  At  the  age  of 
seventeen  the  symptoms  of  locomotor  ataxy  were  dis- 
tinct. There  was  unsteadiness  in  standing  and  walking, 
there  had  been  lightning-pains,  and  no  trace  of  the 
knee-jerk  could  be  obtained.  It  was  difficult  to  ascer- 
tain when  the  symptoms  commenced ;  the  unsteadiness 
had  only  attracted  attention  during  a  year  or  so.  A 


AND   THE   NERVOUS  SYSTEM.  49 

second  case  was  that  of  a  girl  aged  fifteen  (seen  through 
the  courtesy  of  Mr.  Nettleship).  She  had  typical  teeth, 
and  traces  of  characteristic  inflammation  in  cornea  and 
choroid.  The  left  knee-jerk  was  absolutely  lost,  and 
only  a  very  slight  movement  could  be  obtained  on  the 
right  side.  There  was  no  ataxy  or  anaesthesia.  In 
each  iris  the  light  reflex  was  quite  absent,  although 
there  was  full  action  to  accommodation,  and  vision  in 
one  eye  was  normal.  In  another  case  the  disease  was 
thought  to  be  pseudo-hypertrophic  paralysis  because 
there  was  no  knee-jerk  and  the  child  rose  from  the 
floor  with  difficulty. 

Another  malady  of  great  importance  in  regard  to 
which  this  question  has  arisen  is  general  paralysis  of 
the  insane.  The  disease  is  probably  to  be  classed  with 
primary  nerve-degenerations,  but  in  many  cases,  it 
would  seem,  the  secondary  changes  attain  a  very  con- 
siderable independence  of  degree.  Its  close  alliance 
with  tabes  is  shown  by  the  conditions  of  age  and  sex  in 
which  it  occurs,  by  the  degenerative  ocular  palsies 
common  to  the  two,  and  by  their  actual  combination 
in  many  instances.  This  would  lead  us  to  expect  a 
similar  relation  to  syphilis.  The  scientific  proof,  how- 
ever, is  beset  with  many  difficulties.  The  statistics  ob- 
tained have  varied  greatly,  but  no  less  than  75  per  cent, 
of  certain  syphilis  is  described  by  Mendel  in  146  cases. 
A  proportion  almost  as  large  has  been  met  with  by 
others.  One  serious  difficulty  arises  from  the  great  va- 
riations presented  by  the  disease.  Typical  cases  form 
a  minority  of  those  that  may  be  classed  under  the  gen- 
eral name,  and  both  the  typical  and  untypical  forms 
5 


50  LETTSOMIAN    LECTURES   ON   SYPHILIS 

certainly  may  occur  independently  of  syphilis.  I  believe, 
however,  that  syphilis  can  be  traced  in  a  large  propor- 
tion of  each  distinguishable  variety,  although  I  am  not 
able  to  offer  you  any  definite  figures.  Fournier  has 
pointed  out  how  often  symptoms  resembling  more  or 
less  closely  those  of  general  paralysis  seem  to  result 
from  organic  syphilitic  lesions  of  the  brain,  and  I  believe 
that  the  explanation  of  this  is  to  be  found,  less  in  the 
fact  that  the  organic  diseases  cause  these  symptoms, 
than  in  the  profound  degenerative  tendency  which  so 
often  results  from  syphilis.  This  tendency  may  accom- 
pany the  organic  lesion,  and  is  perhaps  sometimes 
actually  excited  by  it.  I  have  occasionally  observed 
that  degenerative  symptoms,  mental  and  articulatory, 
may  distinctly  come  on  soon  after  a  sudden  organic 
syphilitic  lesion,  and  may  subsequently  lessen,  and 
even  pass  away. 

Another  central  degeneration  that  is  probably  an 
occasional  consequence  of  syphilis  is  chronic  muscular 
atrophy,  due  to  degeneration  of  the  motor  cells,  with  or 
without  the  signs  of  lateral  sclerosis.  Great  care  is 
necessary  to  avoid  the  error  of  mistaking  for  this  the 
atrophy  that  results  from  syphilitic  pachy meningitis. 
In  several  cases  that  I  have  seen,  the  true  degenerative 
affection  has  been  an  early  sequel  of  syphilis,  and  no 
other  cause  could  be  traced.  Similar  cases  have  been 
published  by  others,  but  they  do  no  more  than  suggest 
the  relation,  although  they  suggest  it  strongly,  and  my 
own  notes  do  not  enable  me  to  offer  any  statistical  evi- 
dence on  the  question.  The  difficulty  of  the  investiga- 
tion is  increased  by  the  large  number  of  cases  of  senile 


AND   THE    NERVOUS    SYSTEM  51 

character.  The  exclusion  of  these  would  simplify, 
without  hindering,  the  search  for  evidence.  The  inves- 
tigation should  thus  be  restricted  to  cases  commencing 
between  twenty-five  and  fifty,  the  standard  being 
limited  to  the  same  age. 

The  other  common  degenerative  diseases  of  the 
spinal  cord  are  associated  with  syphilis  only,  in  a  pro- 
portion so  small  as  to  raise  a  doubt  whether  there  is 
any  causal  relation  between  the  two.  Nevertheless, 
they  occasionally  follow  syphilis  when  no  other  cause 
can  be  traced. 

This  is  especially  true  of  primary  lateral  sclerosis, 
that  probably  often  underlies  spastic  paralysis.  Ataxic 
paraplegia,  the  combined  effect  of  lateral  and  posterior 
sclerosis,  seems  to  be  very  seldom  preceded  by  syphilis. 

It  must  be  admitted  that  the  relation  of  these  degener- 
ative diseases  to  syphilis  is  a  startling  extension  of  our 
knowledge  of  its  influence.  And  yet,  perhaps,  our 
surprise  is  not  altogether  justified.  Other  facts  exist 
which,  if  they  do  not  lessen  the  marvel,  at  least  may 
prepare  us  for  it.  We  are  familiar  with  the  influence 
of  chemical  poisons  on  certain  parts  of  the  nervous 
system, — with  the  way  in  which  atropine,  curara,  digi- 
talis, and  strychnia  select  for  isolated  derangement 
certain  nerve  elements,  leaving  adjacent  structures 
unaffected.  This  must  be  the  result,  not  only  of  the 
nature  of  the  poison,  but  also  of  the  nature  of  the 
nerve  elements  influenced,  through  which  they,  and 
they  only,  have  a  responsive  susceptibility.  That  an 
organized  virus  may  exert  a  similar  elective  influence, 


52  LETTSOMIAN    LECTURES   ON   SYPHILIS 

the  symptoms  of  hydrophobia  clearly  show,  and  those 
of  whooping  cough  at  least  suggest.  Further,  it  is,  I 
think,  most  important  to  note  that  the  phenomena  and 
pathology  of  diphtheritic  paralysis  demonstrate  that  an 
acute  degeneration  of  certain  nerve  elements  may  also 
be  the  effect  of  an  organic  virus.  We  may  note,  also, 
that  the  effects  of  the  poison  of  diphtheria  sometimes 
so  closely  resemble  those  of  the  poison  of  syphilis,  that 
cases  of  diphtheritic  paralysis  have  been  repeatedly 
mistaken  for  tabes,  and  we  have  seen  that  syphilis  has, 
like  diphtheria,  a  special  tendency  to  derange  an  intra- 
ocular muscle.  Still  further,  in  the  circumstance  that 
the  palsy  is  a  sequel  rather  than  a  concomitant  of 
diphtheria,  we  have  a  fact  that  is  most  significant,  and  a 
fact  whose  significance  is  not  destroyed  by  the  differ- 
ence of  interval  in  the  two  cases,  since  the  difference  of 
interval  is  not  proportionately  greater  than  is  the  differ- 
ence in  duration  of  the  primary  maladies.  Diphtheria 
runs  its  course  in  a  few  days,  and  its  effects  on  the 
nervous  system  are  developed  in  weeks  or  months. 
Syphilis  lasts,  in  the  stage  of  a  blood  disease,  at  least 
for  months,  and  perhaps  for  much  longer,  and  its  effects 
on  the  nervous  system  are  developed  only  in  the  course 
of  years.  But  there  is  possibly  even  more  than  an  anal- 
ogy between  the  effects  of  the  two  diseases.  I  have 
seen  a  few  cases  in  which  there  was  evidence  of  a  per- 
sistent, and  even  a  progressive,  lesion  of  the  spinal  cord 
after  diphtheria,  and  I  have  seen  three  cases  in  whom 
true  primary  atrophy  of  the  optic  nerves,  with  partial 
external  ophthalmoplegia,  was  a  distinct  degenerative 
sequel  to  diphtheria. 


AND   THE   NERVOUS   SYSTEM.  53 

It  may,  I  believe,  be  regarded  as  a  general  law,  and 
a  law  of  much  importance  in  practical  diagnosis,  that 
the  isolated  impairment  of  nerve  structures  that  have  a 
certain  function,  when  acute,  indicates  a  toxic  influence 
— when  chronic,  a  degenerative  process.  It  is  instruc- 
tive to  note  that  these  two  mechanisms  are  not  entirely 
dissociated — that  the  degenerative  process  may  be  the 
late  result  of  a  toxic  agent.  * 

The  problems  we  have  last  considered  have  an 
interest  which  is  at  present,  alas,  purely  scientific.  It 
is  a  strange  anomaly,  this  scourge  of  the  sinister  side 
of  civilized  life.  Its  direct  effects  we  can  control  more 
than  those  of  any  other  malady  of  like  nature,  and  3ret 
both  the  essential  element  of  the  disease,  and  its  remote 

*It  has,  indeed,  become  highly  probable  that  they  are  due  to  a  toxic 
agent  that  is  produced  by  the  syphilitic  organisms,  and  is  left  by  them 
in  the  system — an  agent  that  may  be  a  chemical  material  and  not  an 
"organized  virus."  This  was  suggested  by  Strlimpell.  (Neur.  Cent., 
1889,  p.  547. )  The  theory  agrees  with  the  fact  that  other  acute  specific 
diseases,  more  acute  in  course,  seem  to  have  a  like  effect,  since  they  may 
be  followed,  even  after  some  months,  by  degenerative  multiple  neuritis. 
(See  "Manual  of  Diseases  of  the  Nervous  System,"  vol.  i.)  This 
theory  enables  us  to  understand  why  the  treatment  that  is  so  powerful 
over  the  true  syphilitic  has  no  influence  on  their  degenerative  states 
— a  point  to  which  we  shall  return.  We  can  also  understand  the 
bilateral  symmetry  of  the  symptoms,  so  different  from  the  irregular 
distribution  of  the  true  syphilitic  lesions.  It  is  assumed  that  the 
latter  are  due  to  the  fixation  of  germs  and  their  development  in  the 
tissues,  while  the  degenerations  result  from  the  influence  on  the  nerve 
elements  of  the  toxic  agent  circulating  in  the  blood  reaching  all  parts 
and  affecting  those  that  possess  a  similar  susceptibility,  which,  of 
course,  corresponds  on  the  two  sides. 

The  hypothesis  was  suggested  by  Strlimpell  before  the  delivery  of 
these  lectures,  but  had  not  then  come  to  my  knowledge. 


54  LETTSOMIAN   LECTURES   ON   SYPHILIS. 

effects,  seem  alike  beyond  our  reach.  But  the  knowl- 
edge that  is  not  power  now  may  be  power  in  the  future. 
When  the  specific  organism  has  been  identified  and 
isolated — when  it  has  yielded  the  secret  of  its  life  his- 
tory— then  we  may  look  for  means,  if  not  of  destroying 
it,  at  least  of  modifying  its  processes  and  effects,  and  of 
modifying  them  not  only  in  the  experimenter's  flask, 
but  within  the  human  body.  Until  this  can  be  accom- 
plished, the  light  of  research  does  but  reveal,  in  vaster 
range  and  more  complete  detail,  the  grim  features  of 
the  malady.  Still,  the  light  is  welcome.  We  see  how 
far  the  grasp  of  the  disease  extends  into  regions  believed 
to  be  beyond  its  reach.  We  see  how  long  its  conse- 
quences endure,  and  that  they  live  on  after  the  disease 
itself  has  ceased  to  be  a  power  for  evil,  but  we  see  also 
how  much  more  vast  than  was  formerly  conceived 
will  be  the  saving  influence  of  prevention  or  of  cure, 
when  the  knowledge  that  is  power  is  in  our  hand. 


LECTURE  II. 

MR.  PRESIDENT  AND  GENTLEMEN, — From  the  ques- 
tions of  pathology  and  causal  evidence  that  occupied 
us  in  the  last  lecture  we  pass  to-night  to  subjects 
of  more  immediate  practical  interest — those  of  symp- 
toms and  diagnosis.  The  transition  may  perhaps 
bring  with  it  a  sense  of  relief,  but,  unfortunately,  it 
brings  with  it  no  escape  from  the  difficulties  in  which 
the  subject  is  involved,  and  which  surround,  not  less 
closely  and  scarcely  less  consciously,  its  practical 
aspects. 

First,  however,  I  should  supply  one  omission  in  the 
last  lecture.  To  the  long  list  of  maladies,  the  certain 
or  supposed  consequences  of  syphilis,  should  be  added 
some  of  the  functional  diseases  of  the  nervous  system. 
By  some  authorities  it  is  thought  that  such  diseases 
as  epilepsy,  hysteria,  insanity,  and  neuralgia,  in  their 
purely  functional  form,  are  frequent  consequences  of 
the  influence  of  the  virus  on  the  nerve  elements 
during  the  period  of  its  greatest  activity.  Time  fails 
me  for  any  discussion  of  the  subject,  but  there  are 
two  points  that  are  especially  important  in  any 
examination  of  the  subject.  The  first  is  that  if  any 
special  forms  of  functional  disease  seem  to  be  ex- 
clusively related  to  syphilis,  it  is  essential  that  the 
positive  evidence  from  the  side  of  syphilis  should 

55 


56  LETTSOMIAN    LECTURES   ON   SYPHILIS 

be  supplemented  and  confirmed  by  negative  evidence 
that  these  special  and  peculiar  forms  do  not  occur 
apart  from  syphilis.  Secondly,  if  the  forms  asso- 
ciated with  syphilis  are  not  special,  it  is  needful  to 
consider  most  carefully  the  question  of  indirect  causa- 
tion. The  causes  of  these  diseases  are  many  and 
various,  and  they  are  widely  prevalent.  Some  of  the 
most  potent'  are  involved  in  the  conditions  and  influ- 
ences inseparable  from  constitutional  syphilis  and  its 
treatment,  in  which  physical  depression  and  mental 
annoyance  are  sometimes  combined  with  a  reaction 
from  a  life  of  intense  excitement  of  body  and  mind. 
It  is  also  necessary  to  ascertain  and  allow  for  every 
traceable  predisposition,  and  likewise  to  see  that  the 
therapeutic  evidence  is  secured  from  fallacy  by  a  rigid 
observance  of  the  conditions  that  were  mentioned  in 
the  last  lecture  as  being  essential.  I  cannot  help 
thinking  that  these  measures  would  alter  consider- 
ably the  aspect  of  much  of  the  evidence  on  which 
the  opinions  rest,  and  would  remove  the  uncertain 
to  an  extent  that  would  reduce  the  certain  to  its 
vanishing  point. 

In  the  diagnostic  study  of  symptoms  we  still  feel 
the  pressure  of  the  antagonism  I  mentioned  at  the 
outset.  The  success,  incomplete  though  it  be,  with 
which  we  are  able  to  treat  syphilitic  diseases  of  the 
nervous  system,  renders  it  impossible  to  obtain  a 
knowledge  of  their  symptoms  as  extensive  or  as 
certain  as  we  have  gained  in  the  case  of  most  other 
maladies.  We  can  attain  certainty,  or  at  least  the 


AXD    THE    NERVOUS    SYSTEM.  57 

high  probability,  which  in  medicine  has  generally 
to  do  duty  for  certainty,  only  by  confining  our  atten- 
tion to  cases  in  which  post-mortem  evidence  places 
the  nature  of  the  disease  beyond  doubt.  But  if  we 
thus  restrict  our  attention  to  these  certain  facts, 
and  our  inferences  to  the  sure  conclusions  we  can 
draw  from  those  facts,  our  knowledge  will-  be  at  once 
small  in  extent  and  imperfect  in  character.  It  will  be 
based  only  or  chiefly  on  cases  of  great  severity,  and 
the  effects  of  slighter  forms  and  degrees  of  disease 
will,  to  a  large  extent,  escape  us.  If  we  include  the 
latter  in  our  investigation,  we  are  upon  ground  which 
is  always  insecure,  and  often  treacherous ;  for  an  un- 
certainty, varying  with  the  knowledge  and  care  of  the 
observer,  will  attach  to  a  large  number  of  our  conclu- 
sions. This  uncertainty  ought  to  be  frankly  admitted. 
If  we  recognize  its  existence,  if  we  employ  the  prob- 
able conclusions  as  such,  and  do  not  impute  to 
them  the  certainty  they  lack,  we  may  use  them,  or 
many  of  them,  without  much  risk  of  being  misled. 
To  obtain  the  greatest  practical  power,  we  must,  on 
the  one  hand,  be  often  content  wTith  probabilities 
that  are  not  high,  but,  on  the  other  hand,  we  must 
use  these  probabilities  as  such,  and  trust  them  only  so 
far  as  their  nature  warrants.  Thus  we  may  obtain 
knowledge  of  the  highest  value,  in  which  we  can  place 
implicit  confidence. 

In  the  practical  diagnosis  of  these  diseases,  just  as 
in  their  scientific  investigation,  it  is  necessary  to  weigh 
carefully  each  step  in  the  reasoning,  and  to  do  so  far 
more  carefully  than  in  the  case  of  many  other 

6 


58  LETTSOMIAN    LECTURES   ON   SYPHILIS 

maladies.  Remember  that  the  amount  of  conscious 
and  deliberate  attention  to  the  process  of  inference, 
which  it  is  desirable  to  give,  varies  much  in  different 
kinds  of  disease.  It  should  always  be  reduced  to 
the  least  amount  that  is  consistent  with  safet}r,  but 
no  further.  So  far,  however,  we  must  go.  Did 
we  weigh  with  care  each  step  in  every  diagnostic 
act,  the  limits  of  patience  and  of  life  would  be 
reached  before  a  quarter  of  the  work  had  been 
done  that  might  otherwise  be  accomplished.  Here, 
as  so  often,  our  proceeding  has  to  be  based  on  a  com- 
promise between  the  ideal  and  the  adequate.  Uncon- 
scious inference  enters,  of  course,  largely  into  the 
simplest  so-called  "  observations,"  and  into  such  diag- 
nosis as  seems  to  consist  of  pure  observation.  Still 
larger  is  the  share  it  takes  in  the  recognition  of 
diseases  that  are  inaccessible  to  direct  observation, 
and  yet  yield  "physical  signs"  of  their  presence. 
But,  in  the  latter  case,  we  can  allow  it  to  remain 
unconscious  without  much  risk  of  error,  and  we 
habitually  do  so,  and  even  speak  of  "  finding "  a 
pneumonia  or  a  pleurisy  without  a  suspicion  of  error 
in  our  language,  although  we  really  infer  the  existence 
of  the  lesion  by  a  series  of  mental  processes  that  would 
be  of  considerable  length  if  the  steps  were  distinguished. 
Our  short  cuts,  in  such  cases,  involve  little  danger  to  an 
observer  who  has  been  properly  trained.  But  the  lesions 
in  the  nervous  system  are  wholly  beyond  the  range  of 
observation,  however  aided,  and  with  all  our  looseness 
in  the  use  of  words,  we  do  not  speak  of  "  finding "  a 
cerebral  hemorrhage,  or  even  a  cerebral  tumor,  during 


AND   THE    NERVOUS   SYSTEM.  59 

life.  In  purely  inferential  diagnosis,  in  which  the 
disease  manifests  itself  only  by  effects  that  are  not 
only  indirect,  and,  indeed,  often  doubly  indirect — 
the  effects  of  effects  of  .the  lesion — we  cannot  dis- 
pense with  the  careful  consideration  of  each  step  we 
take.  This  statement  is  eminently  true  of  the  dis- 
eases we  are  now  considering,  because  in  them  we 
have  to  deal  not  only  with  the  character  of  the 
lesion,  but  also  with  its  nature. 

The  fact  indicated  in  the  last  words  is  the  first  im- 
portant consideration  in  regard  to  the  nature  of  the 
diagnostic  process.  The  process  is,  and  must  be,  always 
a  double  one.  Of  the  two  parts,  one  should  always  be 
taken  before  the  other.  We  should  always  ask  what  is 
the  seat  and  what  is  the  nature  of  the  morbid  process, 
before  we  attempt  to  decide  whether  or  not  it  is  specific 
and  due  to  syphilis.  In  greater  detail,  the  essential 
steps  are  these :  (1)  What  is  the  seat  of  the  lesion,  as 
indicated  by  the  symptoms,  and  what  is  its  nature  as 
shown  by  their  course?  (2)  Is  the  process  thus  indicated 
one  of  those  that  may  be  syphilitic?  (3)  Has  the  patient 
had  syphilis  ?  (4)  Can  any  other  cause  of  such  a  morbid 
process  be  traced?  (5)  Lastly,  and  subsequently,  we 
have  to  see  whether  the  result  of  treatment  confirms 
our  conclusion.  The  last  element  is  different  from  the 
rest  in  character  and  separate  in  time.  Its  considera- 
tion involves  questions  that  will  come  under  our  notice 
in  the  next  lecture,  and,  moreover,  are  those  we  exam- 
ined in  considering  the  scientific  use  of  the  therapeutic 
test.  They  need  not,  therefore,  detain  us  to-day.  But  the 
other  steps  we  must  consider  in  the  abstract,  because 


60  LETTSOMIAN    LECTURES   ON   SYPHILIS 

the  only  mode  of  avoiding  error  in  these  cases,  and  of 
reaching  as  sure  a  conclusion  as  the  conditions  permit, 
is  to  treat  each  case  as  a  new  problem,  irrespective  of 
other  cases  or  generic  types,  and  to  work  it  out  by  tak- 
ing each  step  separately — comparing  the  steps  only  at 
the  end  of  the  process. 

One  of  these  questions — whether  any  other  cause  can 
be  traced — may  seem  superfluous,  when  we  are  dealing 
with  processes  that  have  no  other  cause  than  syphilis. 
But  this  statement  of  "  no  other  cause  "  is  true  only  of 
the  pathological  lesion.  Most  syphilitic  processes  have 
their  analogues  in  processes  that  are  not  syphilitic. 
The  effects  of  the  two  on  the  nerve  elements  may  be 
the  same,  and  the  symptoms  due  to  those  effects  may 
be  the  same.  A  gumma  of  the  cortex,  and  a  glioma  in 
the  same  part,  may  produce  identical  symptoms.  The 
consequences  of  the  occlusion  of  an  artery  by  s}rphilitic 
disease  and  by  embolism  may  absolutely  correspond. 
The  element  of  specificity,  therefore,  is  absent  during 
life.  There  are  no  symptoms  of  which  we  can  say,  as 
we  can  of  post-mortem  aspect,  "  this  proves  a  specific 
lesion."  There  are  no  symptoms,  and  no  combinations 
of  symptoms,  produced  by  syphilis,  that  are  not  also 
produced  by  other  causes. 

While  all  specific  processes  have  their  simple  ana- 
logues, there  are  many  simple  processes  that  have  no 
specific  analogues,  and  many  of  these  are  manifested 
by  characteristic  symptoms.  Some  of  these  simple 
processes  may  be  due  to  syphilis,  as  we  have  seen,  but 
even  then  they  are  not  specific ;  so  far  as  we  can  dis- 
cern, they  are  simple.  If  they  are  due  to  syphilis,  they 


AND   THE    NERVOUS    SYSTEM.  61 

are  certainly  not  influenced  by  treatment  as  the  specific 
lesions  are.  Tims,  while  there  are  no  symptoms  that 
prove  a  specific  lesion,  there  are  many  symptoms  that 
prove  that  a  lesion  is  not  pathologically  specific. 

Hence  arises  the  paramount  importance  of  consider- 
ing, in  the  first  instance,  what  kind  of  lesion  the  symp- 
toms indicate.  To  neglect  this  question,  to  conclude 
that  because  a  patient  has  a  disease  of  the  nervous 
system,  and  has  had  syphilis,  the  disease  is  syphilitic, 
is  a  proceeding  precisely  the  same  as  if  we  assume  that 
a  sore  throat  is  syphilitic  without  looking  at  it.  If  a 
syphilitic  person  has  an  attack  of  hsematemesis,  it 
would  not  be  considered  quite  logical  to  assume  at  once 
that  the  hrematemesis  was  of  syphilitic  origin,  and  yet 
observed  facts  actually  afford  more  justification  for  this 
opinion  than  for  the  conclusion  that  paraplegia  of 
absolutely  sudden  onset  is  due  to  syphilis.  We  know 
that  syphilis  has  caused  hemorrhage  into  the  stomach, 
but  we  are  not  certain  that  it  has  caused  hemorrhage 
into  the  spinal  cord. 

Thus  a  consideration  of  the  kind  of  lesion  that  must 
exist  to  cause  the  symptoms  may  enable  us  to  say  one 
of  two  things — either  that  the  process  is  one  that  may 
be  specific,  or  that  it  is  one  that  cannot  be  specific.  To 
deal  with  these  indications  in  detail  would  be  to  enter 
into  the  whole  region  of  the  diagnosis  of  diseases  of  the 
nervous  system.  There  are,  however,  two  conditions 
to  which  almost  all  specific  lesions  conform,  one  of 
time,  the  other  of  place.  First,  true  specific  lesions  are 
generally  either  sudden,  or  sub-acute,  or  sub-chronic. 
An  acute  onset — acute,  not  actually  sudden — practically 


62  LETTSOMIAN    LECTURES   ON   SYPHILIS 

means  acute  inflammation,  and  we  saw  in  the  first  lec- 
ture that  the  occurrence  of  acute  syphilitic  inflamma- 
tion must  be  considered  as  still  sub  judice.  As  a  matter 
of  fact,  the  symptoms  of  certainly  specific  lesions  very 
seldom  develop  to  a  considerable  degree  in  less  than  a 
week.  They  are  also  very  seldom  actually  chronic — 
seldom  occupy  more  than  three  months  in  develop- 
ment. An  actually  sudden  onset,  however,  is  not  at 
all  rare  ;  it  is  the  common  onset  of  the  symptoms  due 
to  vascular  occlusion.  With  these  exceptions,  when 
symptoms  develop  in  a  few  days  or  many  months,  they 
are  not  likely  to  be  due  to  a  true  specific  lesion.  The 
degenerative  sequels  are,  of  course,  chronic  in  onset, 
but  they  are  not  truly  specific.  Moreover,  the  chronic 
interstitial  inflammations,  doubtfully  specific,  are  also 
chronic. 

Secondly,  as  to  place.  The  specific  processes  are,  as 
we  have  seen,  outside  the  nerve-elements,  and  they 
have  therefore  no  special  relation  to  the  nerve-functions. 
Hence  their  effects  are  random  in  distribution.  They 
are  related  to  a  special  function  only  when  that  func- 
tion is  subserved  by  one  region,  and  this  is  so  rare 
as  to  be  of  little  practical  importance.  As  a  general 
rule,  if  we  find  certain  structures  of  common  function 
selected,  for  isolated  impairment  from  among  others  of 
different  function,  we  may  be  sure  that  we  have  not  to 
deal  with  a  true  specific  process.  It  may  be  a  post- 
syphilitic  degeneration,  but  it  is  not  a  really  specific 
lesion.  These  two  indications  are  thus  chiefly  of  im- 
portance as  enabling  us  to  exclude  processes  that  are 
not  syphilitic. 


AND   THE   NERVOUS   SYSTEM.  63 

Assuming  that  we  have  evidence  of  a  process  that 
may  be  specific,  we  can  often  go  a  step  further,  and  say 
that,  from  the  symptoms,  it  is  likely  to  be  specific.  But 
before  doing  this,  it  is  desirable  to  ascertain  whether, 
in  the  case  before  us,  this  possible  cause  can  be  traced 
The  lesion  may  be  due  to  syphilis — is  this  particular 
cause  an  actual  antecedent  in  the  case  before  us  ?  In 
every  department  of  diagnosis,  the  fact  that  a  certain 
cause  can  be  traced  may  always  justly  be  allowed 
weight.  It  must  never  take  precedence  of  more  direct 
evidence  of  the  nature  of  the  lesion ;  but  in  due  sub- 
ordination, it  is  an  indication  of  great  value.  Hence 
the  next  question  is,  has  the  patient  had  syphilis? 
At  least,  this  is  the  form  in  which  the  question  is  com- 
monly put ;  and  in  many  cases  this  form  is  sufficient. 
But  we  must  not  be  content  with  a  negative  answer. 
We  have  already  seen  that  some  of  those  who  have 
had  syphilis  do  not  know  it.  We  cannot  absolutely 
exclude  syphilis  unless  we  can  exclude  infection.  The 
disease  is  so  seldom  contracted  except  in  one  way,  that 
we  need  not  take  other  possibilities  into  consideration. 
Hence,  if  there  has  been  any  possibility  of  exposure  to 
infection,  the  disease  cannot  be  considered  to  be  out  of 
the  question.  The  truth  and  importance  of  this  will 
be  doubted  by  no  one  who  has  seen  much  of  the  late 
effects  of  syphilis,  but  to  those  under  whose  notice  the 
disease  seldom  comes,  it  may  seem  scarcely  credible. 
Indeed,  as  a  matter  of  fact,  few  statements  are  more 
often  doubted. 

In  connection  with  this  point,  the  question  arises, — 
presuming  the  disease  to  be  possible,  what  influence 


64  LETTSOMIAN    LECTURES    ON    SYPHILIS 

should  uncertainty  as  to  the  fact  of  syphilis  have  on 
the  diagnosis?  How  far  should  probability  of  the 
syphilitic  nature  of  the  lesion  be  diminished  by  the 
improbability  of  past  syphilis,  and  vice  versa?  I  think 
that  the  common  error  is  to  allow  too  much  weight  to 
this  element  of  uncertainty,  but  it  is  an  error  that  is 
not  easily  avoided.  The  symptoms,  in  a  given  case, 
are  of  such  a  character  that  their  cause  may  be  a 
syphilitic  process ;  if  the  patient  is  known  to  have  had 
syphilis,  the  syphilitic  nature  of  the  process  seems 
more  probable  than  if  his  syphilis  is  doubtful.  It  is 
right  to  attach  some  weight  to  the  point,  but  the  weight 
should  be  attached  to  the  element  in  the  diagnosis  to 
which  it  properly  belongs — the  element  of  probability. 
It  must  not  be  allowed  to  influence  any  distinct  indi- 
cations of  either  a  positive  or  negative  character.  If, 
for  instance,  the  symptoms  are  such  as  distinctly  indi- 
cate a  syphilitic  lesion,  a  lesion  scarcely  ever  due  to 
any  other  cause,  it  is  evident  that  this  indication  is  not 
really  influenced  by  the  fact  that  the  evidence  of  syph- 
ilis is  inconclusive,  provided  the  disease  is  possible. 
On  the  other  hand,  if  the  symptoms  are  such  as  to 
make  it  most  unlikely  that  the  process  is  syphilitic, 
this  improbability  is  not  materially  lessened,  even  by  a 
certainty  that  the  patient  has  had  the  disease. 

If  the  lesion  is  one  that  may  be  syphilitic — if  pre- 
vious syphilis  is  certain  or  possible — the  question  arises, 
Can  any  other  cause  of  such  a  morbid  process  be 
traced?  If  any  other  cause  exists,  the  difficulty  is 
greatly  increased.  The  diagnosis  then  depends  on  a 
comparison  of  the  precise  character,  first,  of  the  lesions 


AND    THE   NERVOUS   SYSTEM.  65 

produced  by  the  two  causes  with  that  indicated  by  the 
symptoms,  secondly,  of  the  symptoms  by  which  the 
lesions  are  manifested  with  those  presented  by  the 
patient. 

This  abstract  outline  of  the  process  of  diagnosis  may 
seem  to  you  needlessly  complex.  You  may  think  that 
these  considerations  are  purely  theoretical,  but  they 
actually  represent,  in  the  simplest  form,  the  essential 
processes  adopted  in  actual  diagnosis.  I  give  them  in 
the  abstract,  because  their  application  varies  in  each 
case,  and  for  their  effective  use  familiarity  with  their 
principles  is  essential. 

It  must,  however,  be  frankly  admitted  that  exact 
diagnosis  of  the  nature  of  these  specific  lesions  is  some- 
times impossible.  The  symptoms  may  be  equivocal, 
such  as  may  be  produced  by  more  than  one  syphilitic 
process,  but  we  can  generally  narrow  the  probabilities 
to  two  lesions. 

We  may  now  consider  the  symptoms  of  a  few  of 
these  specific  processes.  A  syphilitic  gumma  causes, 
for  the  most  part,  symptoms  like  those  of  any  other  in- 
tracranial  tumor  of  rapid  growth — general  cerebral 
symptoms,  and  focal  symptoms  due  to  the  local  influ- 
ence of  the  growth.  The  special  features  are  never  more 
than  suggestive.  They  depend  on  the  course,  and  also 
on  the  fact  that  gummata  are  rather  more  frequent  in 
certain  parts  than  in  others.  The  course,  like  that  of 
other  specific  lesions,  is  sub-acute  or  sub-chronic ;  the 
seat  is  generally  superficial,  in  the  cortex  or  at  the 
base,  sometimes  within  the  pons,  seldom  in  the  cere- 
bellum, occasionally  in  the  thalamic  region,  growing 


66  LETTSOMIAN   LECTURES   ON   SYPHILIS 

in  from  the  side  of  the  crus.  Hence  symptoms  of 
cortical  irritation  are  relatively  more  frequent  than  in 
other  tumors,  and  convulsions  are  common.  They 
give  most  important  information  from  their  local  dis- 
tribution or  commencement,  or  from  the  aura  that 
equally  indicates  the  spot  at  which  the  discharge 
begins.  But  all  these  indications,  even  when  com- 
bined, furnish  no  absolute  or  even  approximate 
ground  of  distinction.  They  may  be,  and,  indeed, 
often  are,  produced  by  growths  of  other  nature,  espe- 
cially by  gliomata  of  rapid  growth. 

The  indication  of  the  course  of  the  lesion  afforded 
by  the  symptoms  is  chiefly  useful  for  its  negative 
significance ;  a  very  chronic  growth  is  not  likely  to  be 
syphilitic.  On  this  point  we  may  gain  instructive 
information  from  the  optic  neuritis  that  is  so  often 
present,  the  course  of  which  generally  shows  the  course 
of  the  disease  of  the  brain.  Syphilomata  always  cause 
an  acute  form  of  optic  neuritis,  becoming  intense.  A 
rapid  growth  never  causes  a  chronic  form  of  neuritis, 
although  now  and  then  a  slow  growth  may  cause  an 
acute  form.  Hence,  while  acuteness  of  the  neuritis  is 
of  little  diagnostic  value,  chronicity — a  neuritis  that 
remains  for  a  long  time  moderate  or  slight  in  degree — 
is  distinctly  opposed  to  the  diagnosis  of  a  syphilitic 
growth,  and  adds  considerable  weight  to  the  similar 
indication  afforded  by  great  chronicity  of  other  symp- 
toms. This  indication  is  especially  valuable  when  the 
early  symptoms  are  equivocal,  and  we  find  it  difficult 
to  say  how  long  the  tumor  has  existed. 

These  growths   are  among  the   specific  lesions  in 


AND    THE   NERVOUS   SYSTEM.  67 

which  the  effect  of  treatment  is  of  most  diagnostic 
value.  It  usually  causes  a  prompt  diminution  in  the 
symptoms,  but,  to  be  of  significance,  this  diminution 
should  be  considerable,  and  should  involve  both  sets  of 
symptoms,  the  local  and  general.  It  is  a  remarkable 
but  certain  fact,  that  now  and  then  a  considerable 
diminution  in  symptoms  of  other  kinds  of  tumors,  and 
especially  in  the  general  symptoms,  sometimes  follows 
the  administration  of  potassium  iodide.  The  effect  is 
most  frequent  in  gliomata,  and  these  are  the  growths 
that  give  rise  to  most  difficulty.  Sometimes  even  the 
optic  neuritis  may  lessen,  but  more  often  it  is  un- 
changed, and  this  should  put  us  on  our  guard.  In 
estimating  the  significance  of  the  subsidence  of  the 
neuritis,  we  must  remember  that  every  intense  inflam- 
mation, after  it  has  reached  its  height,  slowly  subsides, 
although  the  tumor  that  has  caused  it  continues  to 
grow.  We  must  not  mistake  this  natural  subsidence 
for  the  result  of  our  treatment.  This  therapeutic  diffi- 
culty can  only  be  met  by  waiting  and  watching.  If  any 
of  the  symptoms  return  or  increase,  if  any  symptoms 
persist  that  would  be  readily  influenced  were  the 
growth  syphilitic,  we  must  assume  that  it  is  not  likely 
to  be  of  this  nature.  The  delay  cannot  be  avoided, 
but  it  is  a  grave  disadvantage,  because  the  progress 
of  surgery  has  so  greatly  increased  the  need,  not  only 
for  exact,  but  for  prompt  diagnosis. 

The  chronic  local  meningitis  of  syphilis  causes  dis- 
tinctive symptoms  chiefly  when  it  affects  the  base  of 
the  brain  and  damages  the  cranial  nerves,  or  when,  at 
the  convexity,  it  implicates  the  motor  region.  The 


68  LETTSOMIAN   LECTURES   ON   SYPHILIS 

symptoms  are  such  as  indicate  a  surface  lesion,  and  the 
absence  of  the  signs  of  any  considerable  loss  of  func- 
tion of  the  subjacent  tissue  is  the  chief  distinction 
from  a  gumma  in  the  same  situation.  Especially  when 
the  symptoms  indicate  a  wide  area  of  irritation  with 
merely  superficial  damage,  the  diagnosis  can  be  made 
with  considerable  probability.  This  focal  meningitis 
is  probably  less  frequent  at  the  convexity  than  are 
gummata,  and  it  is  certainly  less  frequent  there  than  at 
the  base  of  the  brain.  In  the  latter  situation  the  most 
important  symptoms  are  due  to  the  damage  to  the 
cranial  nerves,  and  the  most  important  diagnostic 
points  are  well  known.  The  therapeutic  test  is  avail- 
able only  in  recent  cases  of  meningitis.  When  the 
development  of  the  new  tissue  into  fibres  has  set  in, 
this  seems  to  go  on  in  spite  of  treatment,  and  the  inev- 
itable cicatricial  contraction  may  perpetuate  the  damage 
produced  in  the  more  active  stage.  In  a  case  of  focal 
meningitis  that  has  lasted  for  some  months,  although 
it  may  afterward  be  proved  to  be  syphilitic  in  nature, 
the  symptoms  are  generally  influenced  but  little,  and 
occasionally  not  at  all,  by  anti-syphilitic  treatment, 
however  energetic.  The  other  forms  of  meningitis, 
cerebral  and  spinal,  interesting  and  important  as  they 
are,  I  am  compelled  to  pass  over. 

The  inadequacy  of  the  clinical  history  of  a  syphilitic 
lesion,  when  that  history  is  based  only  on  certain 
evidence,  is  conspicuous  in  the  case  of  the  disease  of 
the  walls  of  the  arteries.  The  classical  researches  of 
Heubner,  who  first  placed  our  knowledge  on  this  sub- 
ject on  a  secure  footing,  were  based,  of  necessity  to  a 


AND    THE    NERVOUS    SYSTEM.  69 

large  extent,  on  fatal  cases.  The  clinical  picture,  delin- 
eated from  those  facts,  faithful  as  it  is  so  far  as  regards 
the  effects  of  extensive  and  severe  disease,  is  yet  imper- 
fect as  a  representation  of  the  slighter  and  much  more 
common  consequences  of  the  morbid  process.  Passing 
over  the  former,  because  it  is  well  known  by  description, 
although  now  seldom  met  with.  I  would  ask  your 
attention  to  some  facts  regarding  the  slight  forms.  The 
importance  of  the  early  diagnosis  of  this  condition  is 
unequaled  even  among  syphilitic  lesions.  There  is  no 
luetic  process  that  is  so  likely  to  cause  grave  and  last- 
ing damage,  no  process  the  effects  of  which,  when  once 
produced,  are  so  entirely  beyond  our  power,  and  yet 
can  be  so  surely  averted  by  prompt  treatment.  For 
this  reason,  I  think  it  is  wise  to  devote  more  time  to 
this  than  to  the  other  special  questions,  and  also  because 
it  is  a  disease  in  which  the  diagnosis  during  life  can 
generally  be  made  with  sufficient  confidence  to  give  a 
high  value  to  clinical  facts. 

The  chief  mechanism  by  which  this  process  is  effect- 
ive in  causing  symptoms  is,  as  we  have  seen,  by  the 
sudden  closure  of  an  artery  or  of  a  branch  going  off 
from  the  diseased  spot.  The  suddenness  of  the  closure 
is  no  doubt  due  to  the  fact  that  the  final  occlusion  is 
effected  by  thrombosis,  and  in  this  respect  the  syphilitic 
disease  does  not  differ  from  the  other  common  form  of 
arterial  disease,  atheroma.  The  closure  has  the  usual 
consequence,  sudden  anremia  and  necrosis  of  the  brain 
tissue,  unless  there  be  sufficient  anastomoses  to  permit 
a  collateral  circulation.  This  may  be  either  complete, 
restoring  function,  or  incomplete,  so  that  the  continuity 


70  LETTSOMIAN   LECTUKES   ON   SYPHILIS 

of  the  tissue  is  preserved  only  by  a  process  which  results 
in  sclerotic  induration. 

The  characteristic  symptoms  are  those  of  a  sudden 
focal  lesion  of  the  brain.  Until  the  degenerative 
period  of  life  is  reached,  such  a  sudden  lesion  is  ex- 
cessively rare  except  from  embolism.  Embolism  can 
usually  be  excluded  if  there  is  no  valvular  heart 
disease  or  other  source  of  embolism,  and  if  the  patient 
has  not  recently  suffered  from  a  disease  known  to  cause 
endocarditis.  Hence  it  follows  that  the  occurrence  of 
such  symptoms  in  an  adult  under  forty-five,  who  has 
had  syphilis,  and  has  not  heart  disease,  may  generally  be 
held  to  indicate  syphilitic  disease  of  a  cerebral  artery, 
and  this  diagnosis  may  be  made  with  a  confidence 
possible  in  few  other  syphilitic  lesions.  This  confidence 
is  confirmed  by  the  occasional  opportunities  for  a  veri- 
fication. When,  under  such  conditions,  the  diagnosis 
has  been  made,  and  the  patient  has  subsequently  died, 
the  arterial  disease  has  been  found,  invariably  so  far  as 
my  own  experience  and  reading  have  gone.  It  is  true 
that,  in  rare  cases,  certain  other  causes  of  arterial 
closure  must  also  be  excluded.  I  will  mention  these 
presently ;  they  do  not  really  lessen  the  validity  of  the 
statement  just  made,  since  the  need  for  considering 
them  is  rare,  and  is  generally  obvious.  But  this  confi- 
dence can  exist  only  before  the  degenerative  period  of 
life.  When  this  period  arrives,  other  causes  of  arterial 
closure  come  into  operation,  causes  which  we  cannot 
exclude  with  the  readiness  and  confidence  with  which 
we  can  exclude  embolism.  This  introduces  an  element 
of  doubt  into  the  diagnosis  of  cases  over  forty-five  or 


AND   THE   NERVOUS   SYSTEM.  71 

fifty  years  of  age.  Hence,  in  endeavoring  to  ascertain 
the  history  of  these  cases  from  merely  clinical  observa- 
tion, it  is  desirable  to  confine  our  attention  to  those  in 
which  the  diagnosis  can  be  made  with  most  confidence. 
The  disease  does  occur  during  the  later  period  of  life ; 
we  have  to  recognize  the  fact  in  our  practical  diagnosis. 
It  may  be  that  this  renders  some  of  our  conclusions 
from  the  earlier  cases  imperfect,  but  we  must  accept 
this  imperfection  in  order  to  obtain  as  much  certainty 
as  possible. 

The  following  conclusions  are  based  on  a  series  of 
cases  that  have  come  under  my  own  observation,  ex- 
cluding those  over  forty-five  years  of  age.  The  cases 
are  fifty  in  number,  but  on  some  points,  owing  to  omis- 
sions, the  precise  number  available  for  comparison  is 
somewhat  less.*  The  patients  were  over  twenty-five, 
with  the  exception  of  one,  aged  twenty-one.  Males 
were  to  females  as  three  to  one,  a  proportion  that  may 
not  be  far  from  the  incidence  of  syphilis  itself. 

Many  observers  have  noted  how  various  is  the  inter- 
val between  the  primary  disease  and  the  cerebral 
lesion,  and  the  variation  is  conspicuous  in  this  series. 
In  one  quarter,  the  lesion  occurred  during  the  first  two 
years  after  infection,  and  the  remainder  were  distributed 
during  the  next  twelve  years  (two,  nine  cases ;  three  to 
five,  seven  cases  ;  six  to  ten,  nine  cases ;  eleven  to 
fifteen,  eleven  cases ;  sixteen  to  twenty,  four  cases). 
There  was  an  interval  of  nineteen  years  in  a  man  who 
had  well-marked  syphilis  at  eighteen,  and  at  the  age  of 

*  I  have  seen  many  other  cases  since,  but  I  have  not  had  time  to 
analyze  them. 


72  LETTSOMIAN   LECTURES   ON   SYPHILIS 

thirty-seven  an  attack  of  right  hemiplegia,  while  a 
year  later  paraplegia  came  on  in  a  sub-acute  manner. 
Eighteen  years  intervened  in  a  woman  who,  at  sixteen, 
married  a  man  of  unsteady  habits ;  her  first  two  chil- 
dren were  born  dead ;  hemiplegia  came  at  thirty-five, 
with  an  onset  characteristic  of  arterial  thrombosis. 
The  shortest  interval  was  apparently  only  three 
months,  but  the  case  does  not  seem  otherwise  open  to 
doubt.  A  man,  at  the  age  of  twenty-one,  had  for  the 
first  time  a  chancre — a  distinct  hard  sore,  followed  by 
indolent  enlargement  of  the  glands.  Three  months 
after  the  appearance  of  the  sore  he  had  sudden  hemi- 
plegia, which  slowly  passed  away,  but  was  followed  six 
months  later  by  a  second  attack  on  the  same  side.  In 
these  cases,  as,  indeed,  in  all  those  compared,  a  careful 
search  revealed  no  other  cause.  In  the  only  other  case 
in  which  the  interval  was  less  than  a  year  the  attack 
occurred  six  months  after  infection. 

By  far  the  most  common  effect  of  the  lesion  was  hemi- 
plegia, indicating  disease  of  the  middle  cerebral  artery, 
and  probably  the  closure  of  a  branch  to  the  central 
ganglia.  In  only  one  case  did  convulsions  at  the  onset 
suggest  that  the  damage  was  limited  to  the  cortex. 
(Simultaneous  central  softening  necessarily  prevents 
such  special  indication  of  a  cortical  lesion.)  In  three 
cases  hernianopia  suggested  that  the  arterial  disease 
was  in  the  posterior  cerebral.  It  is  evident,  however, 
that  these  cases  present  only  some  of  the  effects  of 
vascular  disease,  and  do  not  present  at  all  its  gravest 
consequences.  Lesions  may  occur  in  parts  of  the  brain 
where  they  cause  no  focal  symptoms,  and,  on  the  other 


AND   THE   NERVOUS   SYSTEM.  73 

hand,  disease  of  the  basilar  and  vertebral  arteries  suffi- 
cient to  cause  definite  symptoms  is  seldom  survived. 
These  grave  effects,  however,  are  well  known,  and  I 
therefore  pass  them  over.  In  probably  nineteen  cases 
out  of  twenty  the  Sylvian  artery  is  that  by  which 
arterial  disease  causes  symptoms,  a  fact  easily  ex- 
plained, and  of  such  disease  this  series  presents  a  fair 
example. 

The  degree  of  the  paralysis  and  its  course  present 
variations  as  great  as,  and  similar  to,  those  met  with  in 
embolism.  It  may  be  slight  and  transient,  or  severe 
and  then  often  lasting,  with  only  such  recovery  as 
occurs  from  compensation — a  slow  return  of  power  in 
the  leg,  and  some  in  the  upper  arm,  the  hand  remain- 
ing powerless,  or  almost  powerless,  with  late  rigidity. 
I  have  a  few  times  known  two  attacks  of  hemiplegia  to 
occur,  at  intervals  of  months.  Very  rarely  symptoms 
of  some  other  syphilitic  process  coincide  with  the  onset. 
It  is  only  in  such  a  case,  in  which  there  is  reason  to 
suspect  a  gumma,  that  I  have  seen  optic  neuritis.  In 
several  cases  the  patients  have  at  some  other  time 
suffered  from  paraplegia,  such  as  might  be  caused  by 
a  gumma  pressing  on  the  cord. 

The  onset  occurred  during  sleep  in  a  third  of  the 
cases,  a  proportion  nearly  corresponding  to  the  time 
spent  in  the  sleeping  state.  During  the  waking  state 
the  onset  is  seldom  attended  by  loss  of  consciousness; 
it  was  so  attended  in  only  one-tenth  of  the  cases — a 
fact  of  much  importance.  Giddiness  and  vomiting 
were  occasional  accompaniments.  Of  great  signifi- 
cance also  is  the  fact  that  the  onset,  in  more  than  half 

7 


74  LETTSOMIAN   LECTURES  ON   SYPHILIS 

the  cases,  was  preceded  by  headache.  The  pain  was 
usually  great,  and  was  either  general  or  chiefly  on  the 
side  of  the  subsequent  lesion.  It  preceded  the  onset 
sometimes  for  only  a  few  days  or  a  week,  often  for 
several  weeks,  rarely  for  two  or  three  months.  It  is 
apparently  in  some  way  due  to  the  arterial  cli 
itself.  Occasionally,  for  a  day  or  two  before  the  onset, 
there  was  a  slight  tingling  or  other  sensation  in  the 
side  afterward  paralyzed.  Thus,  one  patient,  after  ten 
days  of  severe  headache,  had  repeated  attacks  of  ting- 
ling down  the  side  during  two  days  before  onset. 
The  attack  itself  was  often  quite  sudden,  but  in  some 
cases  it  was  deliberate,  or  occurred  in  two  stages.  The 
following  are  instances  of  these  modes  of  onset : — 

1 .  The  arm  and  leg  became  weak  for  a  few  minutes, 
then  recovered,  and  half  an  hour  later  became  suddenly 
powerless. 

2.  Slight  weakness  came  on,  and  continued  for  six 
days  before  the  sudden  hemiplegia. 

3.  The  leg  became  weak  in  the  evening,  and  during 
the  night  the  arm  became  powerless. 

4.  The  patient  woke  up  one  morning  with   loss  of 
power  in  the  leg,  and  during  the  next  two  days  the 
palsy  spread  gradually  to  the  arm  and  face. 

5.  The  arm  became  suddenly  paralyzed,  and  six  days 
later  aphasia  came  on,  with   a  convulsion,  doubtless 
from  the  occlusion  of  a  cortical  branch. 

The  diagnosis  of  this  disease  chiefly  depends  on  the 
causal  indications,  negative  and  positive,  the  absence  of 
other  causes,  and  the  presence  of  syphilis.  The  evi- 
dence of  therapeutics  here  fails  us.  The  syphilitic 


AND    THE    NERVOUS    SYSTEM.  75 

process  in  the  artery,  and  the  secondary  thrombus  that 
results,  are  wholly  separate  from  the  simple  process  in 
the  brain — the  necrotic  softening  on  which  the  symp- 
toms directly  depend.  Treat  the  patient  as  you  will ; 
remove  as  speedily  and  as  completely  as  possible  the 
disease  of  the  arterial  wall ;  you  cannot  restore  the  cir- 
culation, nor  can  you  avert  the  resulting  necrosis  of  the 
brain  tissue  when  once  the  blood  has  clotted  in  the  ves- 
sel. Compare  two  series  of  cases  of  hemiplegia,  one 
due  to  embolism,  and  the  other  to  this  disease,  and  you 
will  find  that  their  general  course  corresponds,  however 
wise  and  thorough  may  have  been  the  treatment  adopted 
in  the  syphilitic  series.  In  each  series  we  meet  with 
cases  in  which  the  palsy  is  slight  or  transient,  but  these 
are  cases  in  which  the  motor  structures  have  not  been 
involved  in  the  softening,  and  have  only  been  interfered 
with  for  a  time  because  the  lesion  was  adjacent  to  them. 
In  each  series  we  find  cases  of  severe  paralysis,  because 
the  motor  path  was  interrupted  or  the  centres  were 
destroyed.  Hence,  by  your  treatment  you  may  save 
the  patient  from  a  fresh  attack,  or  from  an  extension 
of  the  old  mischief,  but  you  cannot  save  him  from  de- 
struction of  tissue  or  avert  its  effects.  Recognize  any 
warning  there  may  be — the  attack  may  perhaps  be 
prevented,  but  once  the  vessel  is  occluded,  your  treat- 
ment is  powerless  over  the  accomplished  injury.  Thus 
these  are  cases  in  which  the  result  of  treatment  has  no 
diagnostic  significance,  and  if  a  positive  result  seems 
traceable  we  may  be  sure  that  the  improvement  is  a 
coincidence  and  not  a  consequence.  An  illustration 
may  make  this  important  fact  more  definite.  If  the 


76  LETTSOMIAN   LECTURES   ON   SYPHILIS 

illustration  is  hypothetical  it  will  nevertheless  be  felt, 
I  think,  to  be  within  the  bounds,  not  only  of  the  possi- 
ble, but  of  the  probable.  A  man  is  seized  with  sudden 
hemiplegia  due  to  some  embolism,  which  has  caused  a 
small  spot  of  softening  near,  but  not  involving  the  mo- 
tor structures.  The  function  of  these  is  temporarily 
impaired,  as  we  know  commonly  happens  in  such  a 
case.  He  has  undetected  mitral  obstruction,  a  short 
presystolic  murmur  having  escaped  recognition,  also 
not  beyond  the  limits  of  experience.  His  medical  at- 
tendant, who  knows  that  the  patient  has  had  constitu- 
tional syphilis,  believes  that  the  hemiplegia  is  syphilitic, 
and  at  once  gives  him  iodide  of  potassium.  In  two  or 
three  days  there  is  a  distinct  return  of  power  in  the 
limbs ;  the  improvement  goes  on,  and  in  a  month  the 
patient  is  practically  well.  What  will  be  the  strength 
of  the  conviction  on  the  part  of  the  practitioner  that  the 
hemiplegia  was  due  to  syphilis?  Will  it  not  be  almost 
impregnable?  And  yet  it  would  be  wholly  wrong. 
Note,  moreover,  that  had  the  same  lesion  of  the  brain 
been  due  to  syphilis,  his  reasoning  from  the  effect  of 
the  treatment  would  have  been  equally  wrong,  and  yet 
his  conclusion  would  have  been  right.  A  great  deal  of 
error  in  medical  science  (and  not  in  medical  science 
alone)  is  due  to  the  fact  that  correctness  of  a  conclusion 
is  transferred  to  the  reasoning  by  which  it  has  been 
reached. 

The  frequence  of  premonitory  symptoms,  and  of  a 
more  or  less  deliberate  onset,  without  loss  of  conscious- 
ness, furnish  diagnostic  indications  that  are  often  of 
great  importance.  They  are  especially  important  when 


AND    THE    NERVOUS    SYSTEM.  77 

some  other  cause  of  arterial  occlusion  co-exists,  and 
especially  when  a  source  of  embolism  can  be  found. 
Sometimes  heart  disease  is  left  by  rheumatic  fever ;  the 
individual  contracts  syphilis,  and  afterward  has  an 
attack  of  sudden  hemiplegia.  We  are  then  unable  to 
avail  ourselves  of  the  causal  indication,  unless  we  find 
evidence  that  one  influence  or  the  other  has  recently 
been  active  in  the  system,  as  by  recent  embolism  or 
recent  syphilitic  processes  elsewhere.  A  deliberate 
onset  is  strongly  in  favor  of  thrombosis,  and  therefore 
of  syphilitic  disease,  rather  than  of  embolism.  Most 
important  of  all,  however,  are  the  premonitory  symp- 
toms, and  especially  headache.  This,  if  severe,  shows 
that  a  morbid  process  within  the  skull  preceded  the 
onset,  whereas  in  embolism  the  intracranial  condition  is 
normal  until  the  obstructing  particle  is  suddenly  trans- 
ferred from  the  heart  to  the  cerebral  artery.  The  prac- 
tical value  of  this  indication  is  increased  by  the  fact 
that  it  is  not  only  a  common,  but  a  prominent  symptom. 
At  the  same  time  its  absence  is  far  less  significant  than 
its  presence.  This  is  true,  remember,  of  all  symptoms 
commonly  regarded  as  "  characteristic."  Their  absence 
proves  little  when  their  presence  proves  much. 

Apart  from  embolism  and  injury,  sudden  hemiplegia, 
coming  on  between  twenty-five  and  forty-five,  is,  I 
believe,  very  seldom  due  to  any  other  cause  than 
syphilis,  and  its  occurrence  may  justly  raise  a  strong 
suspicion  of  this  disease,  even  in  a  case  in  which  there 
is  no  positive  evidence.  But  this  suspicion  is  stronger 
in  the  case  of  men  than  in  women,  because  in  women, 
less  rarely  than  in  men,  sudden  hemiplegia,  clearly  due 


78  LETTSOMIAN    LECTURES   ON   SYPHILIS 

to  an  organic  lesion,  sometimes  comes  on  when  we  can 
trace  no  source  of  embolism,  and  can  exclude  syphilis. 
Now  and  then  the  onset  is  accompanied  by  that  form 
of  pyrexia  which  suggests  septicaemia,  and  actual  proof 
of  this  may  be  furnished  by  the  characteristic  retinal 
hemorrhages.  A  softened  clot,  in  some  situation,  is 
the  most  probable  cause  of  the  symptoms,  and  the 
hemiplegia  may  be  regarded  as  embolic.  But  there  are 
other  cases,  in  which  the  onset  is  unaccompanied  by 
any  symptom  to  suggest  embolism.  I  have  seen 
several  such  cases  in  girls  between  eighteen  and  thirty, 
in  whom,  from  history,  character,  and  life,  inherited  or 
acquired  syphilis  could  be  absolutely  excluded.  The 
hypothesis  of  thrombosis  in  a  healthy  artery,  due  to 
some  general  condition,  seems  perhaps  the  least  im- 
probable explanation  of  such  cases.  But  if  the  sub- 
ject of  such  a  palsy  happens  to  be  a  girl  of  the  lower 
classes  the  diagnosis  of  probable  syphilis  is  not  unlikely 
to  be  made,  and  the  more  readily  because  we  cannot 
exclude  the  risk  of  infection  in  the  case  of  unmarried 
women  as  we  can  in  unmarried  men. 

With  the  advent  of  the  degenerative  period  of  life 
comes  an  enormous  accession  of  difficulty  in  diagnosis. 
After  the  age  of  forty-five  or  fifty  is  passed,  we  can  never 
feel  sure  that  we  are  not  in  the  presence  of  the  changes 
in  the  arteries  which  cause  cerebral  hemorrhage  or  cere- 
bral softening.  The  difficulty  is  further  increased  by  the 
fact  that  syphilitic  disease  becomes  not  only  relatively 
but  absolutely  less  frequent,  so  that  the  likelihood  of  it 
does  not  help  the  observer,  as  at  an  earlier  period  of  life. 
Hence,  when  it  does  occur  it  is  more  likely  to  be  unsus- 


AND    THE   NERVOUS    SYSTEM.  79 

pected  and  unrecognized.  This  is  indeed  one  of  the 
ohief  practical  risks  of  error,  for  the  diagnosis  can  still 
be  made  in  most  cases,  although  less  surely.  The 
diagnostic  indications  that  are  often  distinct  and  im- 
portant in  the  earlier  period  of  life  are  equally  common 
and  equally  significant  in  the  later  period.  The  sig- 
nificance of  some  of  them  is  indeed  not  so  strong  as  in 
early  adult  life,  but  their  relative  importance  is  greater, 
since  on  them,  and  especially  on  those  that  are  still 
unequivocal,  the  diagnosis  chiefly  depends.  Their  sig- 
nificance is  strengthened  by  a  history  of  syphilis,  but 
this  history  alone  has  far  less  value  than  at  an  earlier 
age.  Further,  as  we  cannot  exclude  syphilis  merely 
because  there  is  no  history  of  it,  so  we  cannot  ex- 
clude the  degenerative  lesions  merely  because  degen- 
eration is  not  manifest.  Hence  arises  the  extreme 
importance  of  the  diagnostic  indications  afforded  by 
the  mode  of  onset  and  premonitory  symptoms,  taken, 
of  course,  in  combination  with  the  general  diagnostic 
indications  that  apply  to  all  sudden  lesions  in  late 
life.  The  absence  of  coma,  the  frequent  occurrence  of 
prodromata,  or  a  deliberate  development  of  the  palsy, 
together  with  the  state  of  the  heart,  may  render  hemor- 
rhage unlikely,  and  the  chief  difficulty  is  the  distinction 
from  atheromatous  softening.  In  this,  as  in  syphilitic 
disease,  a  morbid  state  of  the  arteries  exists  before  the 
sudden  onset,  and  these  may  cause  slight  premonitory 
symptoms  analogous  to  those  we  have  been  considering. 
But  headache  is  not  very  common,  and  is  never  so  con- 
siderable as  it  very  often  is  in  syphilitic  disease.  Athe- 
romatous softening,  moreover,  is  essentially  a  senile 


80  LETTSOMIAN   LECTURES   ON    SYPHILIS 

malady.  Apart  from  kidney  disease  or  an  early  degen- 
erative tendency,  usually  conspicuous,  it  is  not  often 
met  with  under  sixty,  and  it  becomes  more  frequent  as 
life  advances  and  the  syphilitic  lesion  becomes  more 
and  more  rare,  till  at  last  it  is  only  to  be  thought  of 
when  special  circumstances  suggest  its  possibility. 

The  application  of  these  principles,  varying  as  it  does 
in  detail,  I  must  leave ;  but  I  may  mention  to  you  a 
case  which  shows  very  well  their  use  and  value.  By  a 
curious  and  convenient  coincidence,  this  case,  one  of 
the  best  unverified  illustrations  of  this  particular  diag- 
nostic difficulty  that  I  have  ever  met  with,  came  under 
my  notice  as  I  was  finishing  this  part  of  my  lecture. 
Dr.  Barnes,  of  Ewell,  asked  me  to  see  with  him  a  woman, 
forty-two  years  of  age,  in  whom,  two  days  before,  right 
hemiplegia  had  come  on  in  the  course  of  a  few  hours, 
without  loss  of  consciousness.  The  face  was  not 
affected  on  the  right  side,  and  this  fact,  with  distinct 
weakness  of  the  left  side  of  the  face,  diplopia,  tingling 
of  the  left  hand,  and  frequent  hiccough,  made  it  almost 
certain  that  the  lesion  was  in  the  pons.  The  urine  had 
for  some  years  contained  albumin  and  granular  casts. 
In  the  left  eye  were  the  remains  of  syphilitic  choroiditis, 
and  one  child  had  been  born  dead  without  traceable 
cause.  For  several  months  she  had  suffered  much 
from  headache,  of  increasing  severity,  and  had  become 
much  stouter. 

Here,  then,  we  had  evidence  of  a  lesion  which  was 
probably  softening  and  not  hemorrhage,  on  account  of 
its  position,  and  of  the  deliberate  onset,  without  loss  of 
consciousness ;  hemorrhage  into  the  pons  causing  more 


AND    THE    NERVOUS    SYSTEM.  81 

severe  initial  symptoms,  which  are,  moreover,  seldom 
survived  for  more  than  a  few  hours.  Hence,  the  most 
probable  lesion  was  disease  of  the  basilar  artery,  with 
thrombosis  in  some  of  its  branches.  For  such  arterial 
disease  we  had  two  adequate  causes — renal  mischief 
sufficient  to  render  atheroma  probable  at  her  age,  and 
syphilis.  There  was  no  evidence  of  recent  active  syph- 
ilis, and  the  balance  of  probability  was  strongly  in 
favor  of  atheroma,  by  reason  of  the  greater  average 
frequency  of  this  affection  under  these  circumstances 
and  causal  conditions.  But  there  was  one  symptom  of 
a  positive  character,  the  significance  of  which  no  mere 
probability  or  improbability  could  be  allowed  to  influ- 
ence— the  severe  and  persistent  headache.  Kidney 
disease  will  cause  headache,  but  not  such  headache  as 
this  patient  had  suffered  from,  which  had  kept  her 
awake  at  night  repeatedly,  and  was  often  more  severe 
on  the  left  side  of  the  head  than  on  the  right.  It  was 
a  symptom  that  suggested  more  than  mere  atheroma, 
and  distinctly  turned  the  balance  of  evidence  in  favor 
of  syphilitic  disease.  The  case  was  clearly  one  of 
urgent  danger,  as  every  case  is  in  which  there  is  an 
active  morbid  process  in  the  pons,  and  I  confess  I  had 
little  hope  that  any  treatment  would  be  of  avail.  But 
we  decided  to  treat  the  patient,  for  a  time,  on  the 
assumption  that  the  disease  was  syphilitic,  and  to 
increase  the  iodide,  which  she  was  already  taking  in 
small  doses,  to  forty-five  grains  a  day,  adding  a  little 
digitalis  to  steady  the  circulation.  If  no  improvement 
could  be  observed  at  the  end  of  a  few  days,  the  dose  of 
8 


82  LETTSOMIAN    LECTURES   ON   SYPHILIS 

iodide  should  be  reduced  again,  lest,  if  no  good  could 
be  done  to  the  wall  of  the  vessel,  the  drug  might  do 
harm  by  increasing  the  tendency  of  the  blood  to  clot. 
But  on  the  third  day  the  patient  was  distinctly  better ; 
the  improvement  steadily  went  on,  and  I  hear  now 
from  Dr.  Barnes  that  she  has  fair  power  in  the  arm  and 
leg,  is  free  from  headache,  and  has  no  symptoms  to 
suggest  anxiety.  Of  course,  it  is  possible  that  the  diag- 
nosis was  wrong,  but  its  method  may  not  be  uninstruct- 
ive,  and  the  result  appears  to  afford  some  confirmation 
both  to  the  principles  and  to  their  application.  At  least 
we  may  see  in  this  case  how  essential  it  is  to  arrive  at 
a  precise  diagnosis  of  the  character  of  the  lesion  before 
the  causal  indications  are  considered,  and  that  this 
need,  always  present,  is  especially  obvious  in  those 
whose  age  or  state  of  health  involves  a  liability  to 
several  lesions.  A  hasty  diagnosis  of  cerebral  hemor- 
rhage in  this  patient  would  probably  have  prevented 
any  significance  being  attached  to  the  indications  of 
previous  syphilis. 

We  may  see  also  how  necessary  it  is  to  give  its  due 
weight  to  each  indication,  how  the  significance  of  one 
may  be  strengthened  by  the  concurrence  of  others,  and 
how  paramount  is  the  necessity  of  limiting  the  influ- 
ence of  mere  probability,  and  not  permitting  this  to 
counterbalance  any  distinct  and  positive  indication. 
Although,  as  I  said,  recovery  does  not  prove  that  a 
diagnosis  is  correct,  this  reservation  must  be  made 
whenever  a  patient  happily  survives.  The  reservation 
applies  only,  moreover,  to  solitary  cases.  The  test  of 


AND   THE   NERVOUS   SYSTEM.  83 

the  reasoning,  afforded  by  the  result,  may  not  be  valid 
in  the  individual  case,  but  in  a  number  of  cases  com- 
bined it  will  not  mislead. 

Another  point  in  the  differential  diagnosis  of  vascu- 
lar disease  should,  however,  be  specially  mentioned, 
because  its  peculiar  and  unusual  difficulty  occasionally 
leads  astray  even  those  who  have  had  much  experience. 
It  is  the  distinction  of  the  slighter  forms  of  hemiplegia, 
or  other  local  symptom,  from  the  unilateral  symptoms 
that  are  common  in  general  paralysis  of  the  insane, 
even  in  the  early  stage  of  the  disorder.  Whatever  be 
their  immediate  cause,  they  do  not  seem  to  depend  on 
an  organic  lesion,  but  the  symptoms  of  an  organic 
lesion  are  sometimes  simulated  by  them  in  a  puzzling 
manner.  The  difficulty  is  increased,  and,  indeed,  is 
largely  due,  to  the  fact  that  so  many  of  the  subjects  of 
general  paralysis  have  had  syphilis. 

Cases  are  not  rare  in  which  this  formidable  disease 
comes  on  while  syphilis  is  manifestly  active ;  it  may 
even  supervene  on  some  actual  syphilitic  lesion  of  the 
brain.  Thus  the  effects  of  syphilitic  vascular  disease 
are  occasionally  followed  by  degenerative  symptoms 
of  various  kind  and  degree.  After  recover}',  complete 
or  incomplete,  fresh  symptoms  may  come  on,  such  as 
failure  of  memory  or  other  mental  change,  or  failure  in 
articulation.  These  symptoms  may  also  commence 
during  recovery  from  the  hemiplegia.  Moreover,  an 
attack  of  hemiplegia,  which  seems  at  the  time  to  be 
due  to  the  common  vascular  disease,  is  occasionally 
followed,  in  the  course  of  a  few  months,  by  symptoms 
of  general  paralysis  of  the  insane  quite  typical  in  char- 


84  LETTSOMIAN    LECTURES   ON   SYPHILIS 

acter  and  course.  For  instance,  a  man  about  eight 
years  after  primary  syphilis  had  an  attack  of  sudden 
hemiplegia,  severe,  and  preceded  by  headache.  In 
the  course  of  a  month  he  recovered  almost  completely, 
and  those  who  knew  him  observed  very  little  difference 
from  his  state  before  the  attack.  A  little  later,  however, 
a  slight  change  in  articulation  attracted  their  notice, 
coupled  with  some  scarcely  definable  alteration  in  his 
mental  characteristics.  A  few  weeks  later  optimistic 
delusions  suddenly  burst  out ;  he  was  about  to  make 
his  own  fortune  and  the  fortune  of  his  friends ;  the 
thousands  and  hundreds  of  thousands  poured  from  his 
lips  in  the  flow  of  magniloquence  we  know  so  well,  a 
flow  that  was  soon  rendered  almost  unintelligible  by 
the  usual  characteristic  failure  of  articulation,  and 
typical  general  paralysis  ran  a  rapid  course  to  its 
common  termination.  In  such  a  case,  if  the  initial 
hemiplegia  is  slight  and  transient,  it  may  be  difficult 
to  say  whether  the  attack  is  due  to  an  organic  lesion, 
or  is  one  of  those  inorganic  attacks  that  occur  in  the 
course  of  this  disease.  Indeed,  the  diagnosis  may  be 
impossible  except  by  waiting  and  watching  the  case. 

Another  difficulty  is  due  to  the  fact  that,  in  general 
paralysis,  attacks  occur  in  which,  instead  of  the  sudden 
weakness  of  hemiplegic  character,  there  are  unilateral 
symptoms  characteristic  of  a  local  "  discharge  "  in  the 
brain.  When  such  discharge  is  so  great  and  so  situ- 
ated as  to  cause  actual  convulsion,  there  is  less  risk 
of  this  particular  error,  but  sometimes  there  are  other 
sudden  symptoms,  more  equivocal  in  character,  such 
as  tingling,  beginning  in  some  part  and  spreading 


AND    THE   NERVOUS    SYSTEM.  85 

through  the  side,  and  accompanied,  it  may  be,  by  in- 
hibitory weakness  or  temporary  aphasia.  Such  attacks 
have  often  been  ascribed  to  syphilitic  vascular  disease. 
The  latter,  however,  does  not  cause  such  definite  limited 
"  discharges  "  as  a  first  symptom.  These  always  sug- 
gest a  chronic  process  and  not  a  sudden  lesion,  and, 
therefore,  in  the  absence  of  signs  of  tumor  or  of 
meningitis,  the  degenerative  malady  should  always 
be  thought  of.  This  is  true  also  if  there  have  been 
similar  attacks,  or  any  change  in  mind  or  speech, 
however  slight. 

Among  the  innumerable  other  diagnostic  problems 
that  invite,  and  almost  demand  consideration,  I  can 
notice  only  one  group,  those  that  relate  to  the  palsies 
of  the  ocular  muscles.  These  are  among  the  most  fre- 
quent manifestations  of  the  influence  of  syphilis  on 
the  nervous  system.  The  long  course  of  the  ocular 
nerves  exposes  them  to  many  kinds  of  specific  damage. 
Arterial  disease  seldom  interferes  with  their  functions, 
and  when  it  does  so,  it  is  only  by  causing  a  sudden 
vascular  lesion,  separable  from  all  others  by  the  com- 
plex associated  derangement  produced,  and  by  the 
actually  sudden  onset.  Gummata  and  local  menin- 
gitis may  damage  the  nerves  at  the  base  of  the  brain, 
and  the  locality  of  the  lesion  is  then  indicated  by  the 
grouping  of  the  nerves  affected  ;  the  two  processes  are 
sometimes  distinguishable  by  the  greater  interference 
with  the  central  organs,  or  with  the  motor  tract  in  the 
cms  and  pons,  and  also  by  the  greater  frequency  of 
optic  neuritis  in  gummata  than  in  meningitis  of  the 
posterior  part  of  the  base.  Optic  neuritis  may  be 


86  LETTSOMIAN    LECTURES   ON   SYPHILIS 

readily  caused  by  meningitis  when  this  is  in  the 
front  part  of  the  base,  so  that  this  distinction  must 
depend  on  the  evidence  of  the  position  of  the  dis- 
ease. Gummata  on  the  nerve  trunks  themselves  can 
scarcely  be  distinguished  from  inflammation.  In  any 
part  of  their  course  they  may  be  the  seat  of  a  syphilitic 
neuritis,  and  this  is  probably  the  most  common  cause 
of  an  isolated  affection  of  a  single  nerve  or  of  a  single 
branch. 

Thus  each  diagnosis  of  this  kind  involves  the  care- 
ful consideration  of  the  symptoms  and  their  combi- 
nations, as  well  as  of  their  mode  of  onset  and  asso- 
ciations. The  subject  is  too  large  for  me  to  do  more 
than  indicate  the  lines  on  which  it  must  be  ap- 
proached. It  needs,  indeed,  to  receive  a  thorough 
investigation  in  the  light  of  pathological  facts  that  are 
scattered  through  medical  literature,  and  which  need 
to  be  greatly  increased  in  number  before  our  diagnosis 
can  be  exact.  The  greatest  difficulties  in  these  cases 
arise  from  the  fact  that  ocular  palsies  are  caused  by 
some  of  the  effects  of  syphilis  that  are  not  specific  in 
their  nature.  For  instance,  an  isolated  palsy  of  one 
third  nerve,  in  a  young  man  known  to  have  suffered 
from  the  constitutional  disease,  was  naturally  sup- 
posed to  be  truly  specific.  But  treatment,  although 
prompt  and  thorough,  had  no  influence  on  it.  One  day 
he  suddenly  became  unconscious,  and  died  in  a  few 
hours.  We  can  scarcely  doubt  that  an  aneurism, 
due  to  syphilis,  caused  the  palsy  and  his  death.  But 
the  most  frequent  non-specific  causes  of  these  symptoms 
are  the  degenerations.  These  may  set  in  before  the 


AND   THE   NERVOUS   SYSTEM.  87 

period  of  true  specific  lesions  has  passed,  and  the 
ocular  nerves  constitute  one  of  the  regions  in  which 
the  symptoms  of  the  two  kinds  most  often  coincide. 
More  frequent  than  actual  coincidence  is  the  doubt 
produced  by  it.  Is  this  palsy  due  to  a  true  specific 
lesion,  or  is  it  part  of  nerve  degeneration  that  is  a  non- 
specific sequel  to  syphilis  ?  The  question  is  of  great 
importance  in  regard  both  to  prognosis  and  to  treat- 
ment. In  cases  of  locomotor  ataxy  that  occur  com- 
paratively early,  this  difficulty  is  especially  frequent. 
The  distribution  of  the  symptoms  may  furnish  an 
answer,  as  we  shall  see  in  a  moment.  Sometimes  the 
suddenness  of  the  onset  raises  a  strong  presumption 
that  the  palsy  is  tabetic  and  not  specific.  The  same 
conclusion  is  indicated  when  symptoms  quickly  lessen 
without  treatment  and  soon  afterward  return. 

The  nature  of  many  of  these  tabetic  palsies  is  doubt- 
ful, but  some  are  certainly  due  to  nuclear  degeneration. 
These,  as  we  saw  in  the  first  lecture,  are  often  sequelse 
of  syphilis.  Their  distinction  from  a  true  specific 
lesion  is  another  problem  of  much  difficulty — a  diffi- 
culty further  increased  by  the  fact  that  nuclear  affec- 
tion seems  sometimes  to  follow  a  peripheral  palsy  so 
directly  that  the  symptoms  of  one  pass  into  those  of  the 
other. 

The  most  important  characteristics  of  the  nuclear 
palsy  are  the  association  of  muscles  according  to  func- 
tion, its  bilateral  distribution,  and  its  persistence  in  spite 
of  treatment.  In  most  true  specific  lesions  prompt  treat- 
ment has  an  influence  which  is  absent  in  the  degenera- 


LETTSOMIAN   LECTURES    ON   SYPHILIS 

tive  maladies.  I  need  not  trouble  you  with  instances 
of  these  features.  They  are  important  distinctions 
both  in  the  isolated  degeneration  and  in  that  associated 
with  tabes.  I  may  add  to  them  the  therapeutic  test, 
which  is  often  of  great  use  in  diagnosis,  but  is  of  nega- 
tive significance  only  when  the  proper  treatment  has 
been  employed  early. 

I  have  said  that  the  nuclear  degeneration  sometimes 
seems  to  follow  a  specific  palsy,  but  it  also  occurs,  as 
we  have  seen,  when  there  has  been  no  paralysis,  so 
that  we  are  perhaps  not  justified  in  connecting  the 
two. 

A  tendency  is  often  to  be  observed  in  the  present 
day  to  underrate  diagnosis,  or  at  least  the  elaborate 
diagnosis  of  which  the  diseases  of  the  nervous  system 
furnish  so  many  examples.  In  the  face  of  the  urgent 
needs  of  suffering  humanity,  with  its  mute  appeal  or 
uttered  cry  for  the  relief  we  cannot  always  give,  our  pre- 
cise distinctions  and  elaborate  processes  may  seem  like 
an  ingenious  device  for  interesting  us  while  the  patient 
suffers.  That  such  an  impression  is  wholly  wrong  I 
need  not  say  to  those  who  hear  me  now.  But  the  ten- 
dency is  real,  and  is  reflected  beyond  our  own  ranks ; 
and  I  may  give  one  warning,  a  warning  to  myself  as 
well  as  to  others,  that  we  should  be  always  on  our  guard 
lest  we  do  anything,  by  word  or  manner,  that  may 
excite  or  foster  the  feeling  to  which  I  refer.  Diagnosis 
must  come  before  treatment,  and  this  should  make  us 
careful  lest  we  produce  an  impression  that  we  regard 
the  order  of  the  two  in  time  as  also  that  of  their  im- 


AND    THE    NERVOUS   SYSTEM.  89 

portance — an  impression  easily  produced  when  the 
treatment  is  plain  and  its  methods  familiar,  while  the 
diagnosis  is  complex  and  its  processes  strange.  But 
surely  the  diseases  we  are  now  considering  supply  a 
strong  reproof  to  those  who  consider  that,  "  to  say  the 
least,  diagnosis  is  somewhat  overdone."  A  diagnosis 
that  can  be  described  as  "  rough  and  ready "  may 
serve  to  make  our  treatment  effective  in  the  majority 
of  cases,  but  there  are  many  in  which  only  a  most 
careful  and  even  elaborate  diagnosis  will  enable  us  to 
do  all  that  can  be  done,  and  there  are  not  a  few  in 
which  the  utmost  degree  of  care  and  elaboration  is 
needed  to  save  us  from  being  wrong  in  our  treatment 
— often  wholly  wrong,  and  sometimes  disastrously 
wrong.  I  could  give  many  instances  of  this,  striking 
and  sad,  but  it  is  needless  to  do  so,  and  it  may  be 
unwise.  My  own  conviction  is  that  diagnosis  in  itself 
cannot  be  overdone.  To  permit  diagnosis  to  be  studied 
and  employed,  at  the  expense  of  treatment,  is  a  pro- 
ceeding for  which  no  words  of  condemnation  are  too 
strong.  To  cultivate,  at  the  expense  of  its  application, 
that  which  has  no  other  end,  should,  in  medicine,  be  a 
sin  beyond  the  reach  of  pardon.  But,  as  a  guide  to 
treatment  and  prognosis,  we  cannot  well  know  too 
minutely  the  seat  of  the  maladies  we  are  treating,  and 
we  assuredly  cannot  know  too  certainly  their  nature. 
Our  art  may  be  all-powerful  to  save:  but  without 
guidance  it  is  useless — a  hand  to  use  without  an  eye  to 
see.  When  the  disease  is  beyond  our  present  means 
the  same  guidance  may  still  be  needed  to  save  the 
patient  from  that  which,  without  power  of  good,  may 


90  LETTSOMIAN   LECTURES   ON   SYPHILIS 

not  be  without  capacity  of  harm,  and  I  believe  that 
there  is  no  point  in  diagnosis,  however  elaborate  it  may 
be,  or  however  superfluous  it  may  seem,  which  is  not 
or  will  not  be,  in  some  case  or  at  some  time,  of  definite 
use  and  perhaps  essential  service  in  enabling  life  to  be 
saved  or  health  restored. 


LECTURE  III. 

MR.  PRESIDENT  AND  GENTLEMEN, — To-night  we  pass 
to  the  final  ends  for  which  we  gain  our  knowledge — 
the  ability  to  foretell  and  to  control  the  future  course 
of  the  malady.  The  attempt  to  define  our  knowledge, 
which  I  proposed  at  the  outset  as  a  chief  object  of  these 
lectures,  will  here  have  results  not,  I  fear,  wholly  satis- 
factory. The  progress  of  science  involves  loss  as  well 
as  gain.  Where  the  ground  seemed  firm  beneath  our 
feet,  and  the  path  before  us  appeared  smooth,  we  may 
suddenly  find  our  footsteps  insecure,  and  that  the 
smoothness  was  apparent  only — an  illusion  due  to  a 
too  sweeping  generalization.  When  we  come  to  know 
thoroughly  this  part  of  the  region  of  medical  science 
we  are  now  traversing,  we  find  the  ground  is  broken 
by  exceptions,  which  we  cannot  ignore  except  at  the 
risk  of  certain  error  and  equally  certain  discredit.  It 
is  not  long  since  the  diagnosis  of  syphilis  as  a  cause, 
and  the  prospect  of  adequate  treatment,  were  held  to 
warrant  a  prognosis  absolutely  favorable  in  almost 
every  form  of  disease  so  produced.  Indeed,  I  am  not 
sure  that  it  is  correct  to  allude  to  this  opinion  only  in 
the  past  tense,  if  we  may  judge  from  the  measures 
some  hopeless  sufferers  are  induced  to  undergo.  We 
see  them  subjected  to  course  after  course  of  similar 
treatment,  each  to  supplement  some  supposed  defect  in 

91 


92  LETTSOMIAN   LECTURES   ON   SYPHILIS 

the  previous  courses ;  we  see  methods  employed  from 
which  it  would  seem  to  be  supposed  that  a  drug, 
administered  thoroughly  in  one  way,  is  still  capable  of 
doing  more  if  only  it  is  introduced  into  the  system  by 
some  other  channel ;  and  we  see  advice  given  which 
suggests  a  belief  that  treatment  powerless  in  England 
will  be  effective  abroad.  If  we  are  so  bold  as  to 
recognize  the  nature  of  the  opinions  that  must  underlie 
such  measures  and  such  advice,  we  can  scarcely  believe 
that  the  old  view  does  not  still  dominate  many  minds, 
and  that,  although  it  may  not  often  make  its  appear- 
ance on  the  surface  as  a  definite  assertion,  it  must  still 
exist  as  an  undercurrent  of  thought,  adequate  to  guide 
the  practitioner's  advice,  although  perhaps  not  always 
consciously  admitted.  Yet  the  facts  that  are  within 
the  reach  of  simple  observation  suggest  a  very  different 
conclusion.  The  scars  upon  the  skin  or  brow  tell  us 
more  than  the  mere  fact  of  syphilis:  they  tell  us 
unmistakably  of  the  imperfect  character  of  tissue-res- 
toration, and  that,  too  often,  when  the  proper  elements 
of  a  part  have  perished,  their  place  is  and  can  be  sup- 
plied only  by  cicatricial  tissue.  The  internal  organs 
teach  us  the  same  lesson.  The  fibrous  nodule  in  the 
liver  means  a  loss  of  liver-tissue  perhaps  many  times 
the  area  of  the  scar,  and  so  with  other  organs.  When 
such  a  result  occurs  in  the  central  nervous  system,  how 
can  perfect  restoration  of  function  be  expected  or  how 
can  it  occur  ?  In  the  liver  the  effect  on  loss  of  function 
may  be  inappreciable,  but  in  the  nervous  system  each 
cell  and  fibre  has  its  special  use,  and  the  loss  of  a  few 
may  have  effects  on  function  not  only  appreciable  but 


AND    THE    NERVOUS    SYSTEM.  93 

conspicuous.  In  truth,  in  a  very  large  number  of  the 
cases  of  such  lesions,  complete  recovery  of  function 
does  not  and  cannot  take  place. 

Yet  also  in  a  large  number  of  cases  the  symptoms 
pass  away.  Between  entire  recovery  on  the  one  hand, 
and  entire  persistence  of  the  symptoms  on  the  other, 
we  have  every  degree  of  partial  recovery.  The 
course  of  the  disease  in  any  given  case  may  be  any- 
where between  these  two  extremes,  and  if  we  are  to 
foretell  it  aright  we  must  recognize  this  fact,  and  we 
must  learn  where  to  seek  and  how  to  find  the  indica- 
tions that  will  guide  us.  Every  prognosis,  therefore, 
must  be  a  matter  of  special  and  individual  considera- 
tion, just  as  diagnosis  must  be.  No  rule  can  be  laid 
down  applicable  to  all  cases,  and  the  rules  that  can  be 
made  for  any  groups  of  cases  are  limited  and  partial. 
In  each  group,  indeed,  the  general  prognosis  varies,  but 
in  each  group  also  the  individual  case  must  be  dealt 
with  as  a  separate  problem.  So  stated,  the  task  of 
acquiring  any  adequate  prognostic  power  may  seem 
both  difficult  and  long;  but,  happily,  the  power  is 
easily  acquired,  and  its  use  is  simple.  I  said  that  "as 
much  individual  consideration  is  needed  as  in  the 
process  of  diagnosis,"  but  I  should  have  been  nearer 
the  truth  had  I  said  that  the  same  individual  consider- 
ation will  almost  suffice.  Did  the  statements  regarding 
the  process  of  diagnosis  I  made  in  the  last  lecture 
appear  to  you  exaggerated  ?  Surely  they  will  seem 
within  the  truth  when  we  realize  that  a  full  and  correct 
diagnosis  is  not  only  essential  for,  but  actually  almost 
involves,  the  most  complete  and  correct  prognosis  it  is 


94  LETTSOMIAN    LECTURES   ON   SYPHILIS 

possible  for  us,  under  the  circumstances,  to  give. 
Realize  the  nature  of  the  lesion ;  realize  that  the 
symptoms  depend  not  on  the  specific  process,  but  on  the 
simple  effects  that  are  thereby  produced  in  the  nerve- 
tissue  ;  picture  to  yourself  the  changes  that  have  taken 
place,  consider  how  long  they  have  existed,  and  you 
have  only  to  ask  yourselves  how  far  it  is  likely  that 
the  mechanism  of  damage  can  be  removed,  and  how 
far  the  nerve  elements  can  recover  from  the  damage 
they  have  sustained. 

Let  me  repeat  the  injunction,  "  picture  to  yourselves 
the  changes  that  have  taken  place,"  for  its  importance 
is  profound.  Acquire  the  habit  of  forming  a  mental 
picture  of  the  morbid  process  and  the  way  in  which  the 
lesion  is  doing  its  work.  You  will  find  it  of  unspeak- 
able service  to  you  in  giving  you  a  firm  grasp  of  the 
nature  of  pathological  process,  a  grasp  that  will  help 
you  to  a  prognosis  as  adequate  and  a  treatment  as  wise 
and  full  as  the  nature  of  the  case  permits.  This  is  true 
not  only  of  this,  but  of  all  diseases.  To  pass  to  the 
special  prognosis  of  these  diseases,  only  that  of  the  true 
specific  lesions  can  be  now  considered.  It  is  only  in 
these  that  the  fact  that  disease  is  due  to  syphilis  has  an 
extensive  and  considerable  influence.  The  lesions  that 
are  doubtfully  specific,  and  those  that  are  not  specific 
in  their  characters,  do  not  often  respond  to  the  special 
drugs,  and  their  forecast  is  not  influenced  by  their 
causation.  The  specific  processes  alone  will  more  than 
suffice  to  occupy  us.  But  here,  again,  we  meet  at  every 
turn  the  importance  of  precision  in  diagnosis.  We 
must  decide  the  probable  nature  of  any  lesion,  decide 


AND   THE   NERVOUS   SYSTEM.  95 

whether  it  is  specific  or  non-specific,  before  the  ques- 
tions of  prognosis  can  be  even  raised ;  and  we  must 
further  decide,  as  far  as  we  can,  the  precise  form  of 
lesion  that  exists,  before  any  attempt  at  prognosis  is 
possible.  This  done,  the  prognosis  becomes  at  once 
comparatively  simple.  The  fact  that  a  separate  answer 
must  be  given  in  each  case  does  not  involve,  therefore, 
a  mental  process  essentially  different  from  tbat  of  diag- 
nosis. The  special  prognostic  element,  the  process  by 
which  we  read  the  future  in  the  present  and  the  past, 
is  much  the  same  in  all  lesions.  In  brief,  we  have  a 
varying  diagnostic  process,  but  a  prognostic  process 
that  only  differs  in  so  far  as  its  color  and  outline,  and 
not  its  real  form,  vary  with  the  diagnosis.  This,  as. 
indeed,  most  of  the  statements  I  have  made  in  these 
lectures,  are  merely  familiar  facts  in  perhaps  a  fresh 
form.  It  is  strange  how  far  certain  principles,  when 
they  are  definitely  grasped,  will  carry  us,  and  how 
much  they  will  effect  in  their  various  applications. 
Not  seldom  a  change  in  the  form  in  which  a  truth  is 
presented  makes  it  almost  equivalent  to  a  new  truth. 
Hence  I  venture  to  be  so  persistent  in  my  reiterations, 
for  repeat  I  must,  again  and  again. 

Prominent  above  all  the  others  in  prognosis,  there- 
fore, we  must  remember  the  two  leading  principles,  by 
this  time,  I  hope,  familiar  to  you:  first, the  dependence 
of  symptoms  on  the  simple  processes  in  the  nerve  tis- 
sue, and  not  on  the  specific  element ;  secondly,  the  fact 
that  it  is  the  specific  process  only  on  which  our  treat- 
ment exerts  a  direct  influence.  So  the  first  conclusion 
that  we  must  seize  and  hold  fast  is  that  treatment  can 


96  LETTSOMIAN   LECTURES   ON   SYPHILIS 

never  influence  the  symptoms  directly.  The  simple 
processes  that  cause  the  symptoms  are  scarcely  at  all 
amenable  to  direct  treatment,  and  not  at  all  to  the 
specific  treatment.  The  utmost  we  can  do  is  to  try  and 
remove  the  specific  process,  and  so  allow  the  nerve  ele- 
ments to  recover,  if  they  can.  Here,  then,  we  see  the 
essential  principles  that  must  guide  every  prognosis. 
Is  the  specific  process  such,  and  in  such  a  stage,  that 
we  cannot  remove  it  wholly  or  partially  ?  Is  it  to  be 
expected  that  such  removal  of  it  as  we  can  effect  will 
be  followed  by  such  recovery  of  the  damaged  nerve 
tissues  as  will  permit  a  return  of  function?  This  is 
the  method  by  which,  and  by  which  alone,  in  every 
form  and  degree  of  lesion,  our  prognosis  must  be  ob- 
tained. The  process,  thus,  is  simple.  Its  application  is 
not  difficult,  but  it  needs  the  same  exactness,  the  same 
attention  to  every  step,  that  we  have  seen  to  be  requisite 
in  every  practical  proceeding  in  connection  with  these 
diseases.  No  short  road  can  be  found  here,  any  more 
than  in  diagnosis.  We  may  make  each  step  sure  with- 
out any  extensive  special  experience,  but  we  can  only 
do  so  by  patient  care.  Any  senior  student  who  has 
been  properly  trained  may,  in  the  majority  of  the 
cases  of  syphilitic  disease  of  the  nervous  system,  give  a 
prognosis  that  shall  be  nearly  as  correct  as  could  be 
given  by  a  physician  of  large  and  special  experience. 
and  each  must  employ  the  same  process. 

The  first  question  then  is,  how  far  can  the  specific 
process  be  influenced  by  treatment?  We  caught  a 
glimpse  in  the  first  lecture  of  the  variations  that  exist 
in  the  susceptibility  of  the  different  processes  to  treat- 


AND   THE    NERVOUS   SYSTEM.  97 

ment.  We  saw  that  h}>perplasia  is  the  great  character- 
istic of  visible  specificity,  and  that  it  is  this  element  in 
the  process  over  which  treatment  has  most  influence. 
Inflammation,  even  when  it  is  due  solely  to  syphilis, 
seems  to  vary  much  in  its  susceptibility.  Here,  how- 
ever, our  vision  is  limited  by  the  fact  that  we  cannot 
discern,  during  life,  how  much  of  this  apparent  in- 
utility  of  treatment  is  due  to  the  lack  of  influence  over 
the  specific  element,  and  how  far  it  is  due  to  the  fact 
that  the  nerve  elements  cannot  recover.  In  chronic 
inflammation  it  sometimes  seems  as  if  we  cannot  arrest 
the  true  specific  process,  but  in  acute  and  subacute 
inflammations  the  facts  we  can  perceive  and  the  anal- 
ogy of  similar  processes  elsewhere  make  it  probable 
that  the  second  explanation  is  the  true  one  ;  that  it  is 
the  persistence  of  the  damage  to  the  nerve  elements, 
and  not  of  the  lesion  producing  the  damage,  whicl} 
causes  the  persistence  of  the  symptoms. 

The  first  important  consideration,  however,  is  cer- 
tainly the  fact  that  the  tissue-formation  of  syphilis  is 
the  element  that  can  be  influenced  with  most  fre- 
quency, with  most  certainty,  and  in  greatest  degree. 
But  it  is  only  in  the  early  period  of  the  process,  when 
the  tissue  is  still  soft,  that  it  can  actually  be  made  to 
disappear.  When  it  caseates  it  may  also  disappear, 
although  the  removal  of  the  degenerated  particles 
is  perhaps  not  due  directly  to  our  treatment.  When 
and  where  the  process  of  fibroid  transformation  has 
set  in,  it  is  doubtful  whether  our  treatment  does  more 
than  aid  this  process,  which  is  really  cicatricial  in 
nature.  The  tissue  that  is  produced  lessens  in 
9 


98  LETTSOMIAN   LECTURES    ON   SYPHILIS 

amount  whether  we  treat  the  patient  or  not,  but  ap- 
parently only  as  the  shrinkage  takes  place  which  all 
scar  tissue  undergoes,  a  shrinkage  by  which  the 
elements  occupy  less  and  less  space  as  they  change 
from  the  original  cells,  or  their  original  form,  into 
inert  fibres. 

In  the  process  of  sub-acute  and  chronic  inflamma- 
tion, moreover,  the  effect  of  treatment  through  the 
specific  element  is  largely  dependent  upon  the 
amount  of  new  tissue  formed,  and  the  stage  of  de- 
velopment which  this  has  reached.  Inflammation, 
however,  causes  also  direct  damage  to  the  nerve  ele- 
ments, proportioned  to  the  acuteness  of  the  process. 
In  acute  inflammation  it  is  great,  and  seems  to  con- 
stitute the  most  effective  element  of  this  process.  We 
saw  that  in  such  acute  inflammation  there  are  com- 
monly no  true  specific  features.  Our  treatment  has 
only  to  bring  the  acute  inflammatory  process  to  an 
end,  and  if  this  can  be  effected  speedily  enough  there 
is  nothing  further  for  the  special  treatment  to  do: 
there  is  no  new  tissue  for  it  to  remove.  When  we 
have  arrested  the  process  of  inflammation  all  we  can 
do  in  our  treatment  is  to  wait  while  the  nerve  struc- 
tures recover,  and  all  that  we  can  do  in  our  prognosis  is 
to  endeavor  to  form  an  opinion  as  to  whether  they  can 
recover  or  not.  But  when  the  inflammation  is  chronic, 
or,  if  acute  in  onset,  has  lasted  for  a  long  time,  we  have 
to  consider  also  the  tissue  that  may  have  been  formed, 
the  extent  to  which  its  removal  is  possible,  and  the 
effects  which  it  has  produced  on  the  nerve  elements,  as 
well  as  the  degree  to  which  they  can  recover. 


AND   THE    NERVOUS   SYSTEM.  99 

These,  then,  are  the  chief  elements  that  have  to 
be  taken  into  consideration  in  forming  a  prognosis. 
But,  in  addition,  there  is  a  question,  subordinate  to 
the  others  in  actual  position,  but  at  least  equal  to 
them  in  importance.  This  question  is  the  state  of 
the  new  tissue  in  connection  with  its  relation  to  the 
nerve  elements.  You  will  see  what  I  mean  in  a 
moment.  As  I  have  just  said,  when  the  fibroid 
transformation  has  set  in,  treatment  does  not  seem 
capable  of  removing  the  new  tissue,  or  doing  more 
than  hastening  this  cicatricial  process.  But  this  pro- 
cess involves,  as  we  have  seen,  contraction  of  the 
fibres.  If  the  new  tissue  merely  compresses  the  ner- 
vous structures  from  on&  side  this  contraction  is  as  ef- 
fective as  absorption  in  relieving  these  structures  from 
the  damaging  pressure.  But  whenever  the  new  tissue 
encircles  the  nerve  elements  and  encloses  them,  the 
compression  is  actually  increased  by  it.  Thus  the 
healing  of  the  syphilitic  process,  the  recovery  of  the 
essential  syphilitic  lesion,  may  mean  that  the  damage 
to  the  nerve  structures  is  maintained,  and  so  also  are 
the  symptoms  produced  by  that  damage.  After  a 
time,  it  is  true,  there  is  often  a  further  improvement 
in  the  symptoms.  AVhen  the  process  of  contraction  is 
at  an  end,  perhaps  even  before  it  comes  to  an  end, 
nerve  fibres,  at  any  rate,  seem  to  be  able,  in  some 
degree,  to  accommodate  themselves  to  the  new  con- 
ditions, and  although  greatly  narrowed,  may  yet  re- 
gain some  capacity  of  conduction,  which  is  sometimes 
considerable  in  amount  and  goes  on  increasing  for  a 
long  time. 


100  LETTSOMIAN    LECTURES   ON    SYPHILIS 

We  see  a  very  pertinent  illustration  of  these  import- 
ant facts  in  the  eye,  in  the  case  of  common  optic  neu- 
ritis. It  is  common  for  sight  to  fail  more  during  the 
process  of  subsidence  of  the  neuritis  than  when  the 
inflammation  is  at  its  height.  The  inflammation 
produces  a  large  amount  of  new  tissue  in  the  sub- 
sidence of  the  optic  nerve  at  the  papilla.  This  in- 
filtrates the  nerve  extending  between  the  fibres,  and 
the  contraction  of  this  tissue  necessarily  involves 
great  compression  of  the  fibres.  But  when  the  sub- 
sidence has  become  considerable,  when  most  of  the 
swelling  has  passed  away,  some  improvement  in  sight 
commences,  and  often  it  goes  on  slowly  for  many 
months,  and  ultimately  reaches  a  very  considerable 
degree.  But  it  is  also  common,  when  the  compres- 
sion of  the  optic  fibres  is  great,  for  the  ultimate  re- 
covery to  be  incomplete,  and  occasionally  the  amount 
of  vision  that  is  regained  is  even  at  last  very  small. 
In  many  of  the  syphilitic  lesions  of  the  nervous 
s}rsteni  the  processes  which  we  can  see  so  clearly 
in  the  eye,  and  estimate  so  accurately  by  our  tests 
of  vision,  certainly  go  on  in  like  manner,  and  with 
corresponding  effects  upon  the  function  of  the  parts. 

Hence  it  follows  that  whenever  there  is  reason  to 
suppose  that  there  is  new  tissue  which  has  begun  to 
undergo,  or  which  has  already  undergone,  the  process 
of  fibroid  transformation,  and  that  this  new  tissue  is  so 
placed  as  to  surround  either  the  spinal  cord,  the  nerve 
roots,  or  nerve  fibres,  our  prognosis  must  be  influenced 
by  the  considerations  I  have  just  mentioned.  In  all  in- 
flammations that  are  not  actually  acute  or  are  not  brief 


AND   THE    NERVOUS   SYSTEM.  101 

there  is  this  new  tissue.  If  the  inflammation  has  lasted 
for  a  few  weeks  before  treatment  has  been  effective  we 
cannot  assume  that  the  new  tissue  will  be  removed. 
The  amount  of  new  tissue  will  be  proportionate  to  the 
intensity,  extent,  and  duration  of  the  inflammation,  of 
which  other  indications  enable  us  to  judge,  and  we 
must  consider  how  far  the  position  of  the  tissue  is 
likely  to  entail  this  encircling  compression.  Hence, 
until  we  can  see  what  influence  treatment  has  upon 
the  symptoms,  our  prognosis  must  be  deferred,  at  least 
so  far  as  details  are  concerned.  If  improvement  is 
absent  or  slight,  or  when  improvement  begins  to  flag, 
we  must  expect  that  the  degree  of  disturbance  of  func- 
tion which  then  remains  will,  for  a  time,  lessen  only 
in  slight  degree  or  at  a  slow  rate;  that  a  little  further 
improvement  may  take  place  in  the  course  of  time  b_y 
the  functional  adaptation  of  the  nerve  elements  to 
their  new  condition;  but  that  some  amount  of  the 
impairment  of  function  is  not  unlikely  to  remain.  We 
must  recognize  also  the  important  fact  that  when  once 
the  early  and  distinct  improvement  that  follows  our 
treatment  is  at  an  end,  or  even  when  it  has  distinctly 
begun  to  slacken,  it  is  not  likely  that  any  further 
improvement  the  case  will  show  will  be  in  any  degree 
the  result  of  anti-syphilitic  treatment.  I  believe  that 
these  general  principles  are  absolutely  true,  and  I  am 
sure  that  their  recognition  in  practical  work  is  of  the 
utmost  importance.  Their  application  to  any  indi- 
vidual case  will  furnish  an  accurate  and  adequate 
prognosis,  and  as  I  said,  this  application  requires 


102  LETTSOMIAN    LECTURES   ON   SYPHILIS 

rather  care  than  practice,  patience  than  special  knowl- 
edge. 

Thus  three  points  in  every  morbid  process  have  to 
be  considered — the  nature  of  the  tissue  in  the  specific 
lesion,  the  mechanism  by  which  the  nerve  elements 
are  damaged,  and  the  character  of  this  damage.  We 
must  consider  the  nature  of  the  tissue  to  determine  the 
effect  our  treatment  is  likely  to  have  upon  it;  we  must 
consider  the  mechanism  by  which  the  nerve  elements 
are  damaged  to  determine  how  far  the  changes  we  are 
able  to  produce  in  the  specific  tissue  can  relieve  the 
nerve  elements ;  and  we  have  to  consider  the  nature  of 
the  changes  in  these  nerve  elements  to  determine 
whether  it  is  or  is  not  likely  that  they  can  recover 
function  if  completely  relieved  from  the  morbid  influ- 
ence. We  have  seen  that  it  is  by  the  removal  of  new 
tissue,  which  is  still  in  the  early  stage,  by  reducing  the 
bulk  of  such  tissue  when  it  is  exerting  compression, 
and  by  checking  the  process  of  pure  inflammation,  that 
our  treatment  is  effective.  We  have  seen  that  it  is 
when  the  compression  is  from  one  direction  that  the 
reduction  in  bulk  of  the  syphilitic  tissue  has  the 
greatest  effect  in  releasing  the  nerve  tissue  from  the 
influence  of  the  syphilitic  process,  and  that  when  the 
new  tissue  presses  on  them  from  all  sides  the  diminu- 
tion in  its  bulk  is  more  than  compensated  by  the  con- 
stricting contraction  of  the  tissue. 

A  word  or  two  more  seems  needed  regarding  the 
third  element,  the  changes  in  the  nerve  elements  them- 
selves. In  pure  acute  inflammation,  even  when  due  to 


AND   THE   NERVOUS   SYSTEM.  103 

syphilis,  this  is  the  only  point  to  be  attended  to.  In 
the  subacute  and  chronic  inflammation  it  is  secondary 
to  the  considerations  regarding  the  new  tissue  which 
have  just  been  mentioned. 

Note,  once  more,  that  these  changes  are  simple  and 
not  specific,  and  that  it  is  on  them  that  the  symptoms 
depend.  They  may  be  the  simple  breaking  up  of  the 
tissue  elements,  seen  in  simple  inflammation  and  also 
in  necrotic  softening  of  the  brain  from  syphilitic 
disease  of  the  arteries.  The  prognosis  of  this  we  con- 
sidered so  fully  last  time  that  I  need  not  speak  of  it 
further.  Except  in  this  process  of  necrosis,  and  in  the 
very  rare  pure  acute  inflammation,  I  do  not  think  you 
will  find  any  certain  instances  of  change  in  the  nerve 
elements  in  specific  processes  without  a  production  of 
new  tissue.  Secondly,  we  have  the  effects  of  compres- 
sion already  mentioned.  Simple  lateral  compression 
readily  arrests  function,  but  it  seems  to  do  so  by 
producing  alterations  in  the  nerve  elements  that  can 
be  recovered  from  to  a  larger  extent  than  is  possible  in 
any  other  form  of  damage.  Whether  the  axis-cylinders 
persist  or  not,  the  fibres  seem  to  be  able  to  regenerate 
even  after  they  have  been  exposed  to  such  pressure  for 
months.  Lastly,  in  the  damage  produced  by  so-called 
"  hyperplastic  inflammation  "  there  seems  to  be  both 
compression  by  new  tissue  and  also  the  alterations  that 
result  from  the  inflammation  itself,  which  we  have 
already  considered.  The  contraction  of  tissue  that 
encircles  the  elements  keeps  up  the  compression 
originally  caused  by  its  bulk  ;  hence  this,  and  also  the 
persistence  of  the  inflammatory  changes  in  the  nerve 


104  LETTSOMIAN    LECTURES   ON   SYPHILIS 

tissue,  cause  the  effects  of  such  hyperplastic  inflamma- 
tion to  persist  long  after  the  activity  of  the  inflamma- 
tory process  itself  is  at  an  end,  and  even'  long  after 
the  treatment  has  ceased  to  exert  any  influence  over 
the  morbid  process. 

Except  for  another  point,  I  might  content  myself 
with  this  outline  of  the  general  principles  of  prognosis. 
Time  fails  me  to  illustrate  its  use,  but  I  may  briefly 
enumerate  the  general  character  of  the  effect  which 
these  considerations  have  upon  the  special  prognosis  of 
the  chief  kinds  of  lesion.  Afterward  I  will  mention 
the  one  remaining  point  that  has  to  be  considered — the 
modification  of  prognosis  entailed  by  the  irritation  which 
some  lesions  cause. 

The  practical  influence  of  these  facts  upon  the  chief 
lesions  is  as  follows :  syphilitic  growths — gummata — 
can  be  removed  more  completely  than  any  other  lesion, 
and  when  their  influence  is  exerted  by  simple  lateral 
pressure  the  resulting  damage  to  the  nerve  structure  is 
recovered  from  in  the  greatest  degree.  Hence,  in  such 
cases,  the  prognosis  is  good,  unless  the  duration  of  the 
damage  is  very  long,  and  its  degree  is  very  great. 
When  the  growth  infiltrates,  however,  the  problem  be- 
comes similar  to  those  met  writh  in  some  inflammations. 

In  all  forms  of  meningitis  the  prognosis  is  good  ex- 
cept in  so  far  as  relates  to  the  damage  to  nerves  and 
nerve-roots  which  are  surrounded  by  the  newly-formed 
tissue,  and  also  the  damage  to  the  spinal  cord  when  the 
dura  mater  is  greatly  thickened.  In  all  these  cases  the 
effects  and  the  symptoms  commonly  lessen  up  to  the 
point  when  the  contraction  of  the  tissue  comes  into 


AND    THE    NERVOUS   SYSTEM.  105 

operation.  The  effects  of  the  inflammatory  damage, 
and  of  the  early  compression,  lessen,  but  a  residuum  re- 
mains in  most  cases,  and  is  increased  in  some  of  them. 
Although  further  improvement  is  not  uncommon  after 
a  time,  some  permanent  effects  may  remain.  When 
there  is  reason  to  suspect  inflammation  of  the  cranial 
nerves — syphilitic  neuritis — the  prognosis  is  chiefly  in- 
fluenced by  the  duration  of  the  morbid  process.  If  the 
inflammatory  products  are  in  such  a  stage  that  they 
can  be  removed  the  prognosis  is  good ;  they  will  recover 
conducting  power.  If,  however,  there  is  reason  to  sus- 
pect cicatricial  transformation  of  the  new  formation 
into  fibroid  tissue  it  is  improbable  that  the  degree  of 
improvement  will  be  sufficient  to  permit  severe  symp- 
toms to  pass  away  entirety.  The  same  general  prognosis 
is  true  also  of  infiltrating  growths.  In  true  acute  in- 
flammation that  is  treated  early  and  arrested  early,  the 
prognosis  is  the  same  as  in  similar  inflammations  that 
are  not  specific.  The  recovery  or  persistence  of  the 
symptoms  depends  on  the  recovery  or  persistence  of  the 
changes  in  the  nerve  elements  which  are  produced  by 
an  intense  inflammation.  Such  changes  are  simple, 
and  not  specific. 

The  point  which  I  have  left  to  the  last  is  the  prognosis 
of  the  symptoms  of  irritation,  which  forms  so  large  a 
part  of  the  manifestations  of  many  lesions.  The  irrita- 
tion may  be  that  of  nerve  fibres,  causing  pain,  or  that 
of  motor  structures  in  the  cortex  of  the  brain,  causing 
convulsions.  The  irritation  of  nerve  fibres  is  due  to 
the  influence  of  inflammation  in  the  first  instance,  and 
secondly  to  the  influence  of  the  residual  compression  I 

10 


106  LETTSOMIAN    LECTURES   ON   SYPHILIS 

have  spoken  of,  and  it  has  a  course  analogous  to  the 
other  effects  of  this  compression.  It  therefore  need  not 
detain  us.  But  the  irritation  of  the  cortex  which  is 
manifested  by  convulsions  is  of  great  import  in  relation 
to  the  problem  of  prognosis,  and  needs  special  consider- 
ation in  every  case  in  which  its  action  can  be  traced. 
Convulsions  are  often  produced  by  a  syphilitic  lesion 
on  the  surface  of  the  brain ;  they  may  persist  after 
treatment  has  done  all  that  is  possible  in  removing  that 
lesion.  Such  convulsions  are  usually  ascribed  to  a  cica- 
trix  on  the  surface  of  the  brain.  They  are  commonly 
of  local  commencement  or  distribution,  and  a  cicatrix 
does  commonly  exist  at  the  spot  to  which  the  local 
commencement  points  as  that  in  which  the  "  discharge  " 
commences.  But  general  convulsions — always  general 
in  commencement — may  be  the  sequel  to  what  seemed, 
from  the  symptoms,  to  be  diffuse  general  meningitis. 
The  theory  which  is  commonly  held,  that  a  cicatrix 
causes  such  symptoms  by  persistent  irritation,  may  be 
correct,  but  it  is  not  easy  to  understand  perpetual  irri- 
tation by  a  stationary  cicatricial  process,  unless  there 
are  sucli  adhesions  to  the  bone  as  involves  repeated  and 
perpetual  mechanical  disturbance.  The  facts  are  equally 
explicable  on  the  assumption,  which  seems  to  me  much 
more  probable,  that  the  "discharges"  originate  from 
slightly  damaged  nerve  cells,  and  that  the  discharging 
tendency  is  perpetuated  by  the  residual  influence  of  the 
discharges  themselves.  This  view  is  quite  consistent 
with  the  effect  of  the  excision  of  a  cicatrix  in  arresting 
the  attacks,  since  the  removal  of  the  scar  entails  that  of 
the  nearest  and  most  unstable  cells.  Be  the  cause  what 


AND   THE   NERVOUS   SYSTEM.  107 

it  may,  the  effect  is  certain  and  important,  though 
the  symptoms  may  persist  long  after  all  other  symp- 
toms of  a  cortical  lesion,  and  may  even  constitute  in 
effect,  although  not  in  origin,  a  variety  of  epilepsy. 
These  persistent  fits,  especially  when  general,  are  not 
influenced  by  anti-syphilitic  treatment.  Hence  their 
occurrence  must  always  cause  a  special  concern,  and 
should  tinge  your  prognosis  with  a  special  caution. 

A  general  survey  of  the  treatment  of  syphilis,  as 
well  as  the  observation  of  individual  cases,  can  scarcely 
fail  to  impress  one  important  conclusion  on  the  impar- 
tial observer.  It  is  difficult  to  express  this  conclusion 
in  language  not  open  to  misconstruction.  Stated  in  its 
baldest  form,  the  conclusion  is  that  syphilis  is  an  incur- 
able disease.*  Stated  in  the  form  least  liable  to  misin- 
terpretation, and  with  the  limits  of  exactness,  it  is  this : 
There  is  no  real  evidence  that  the  disease  ever  is  or  ever 
has  been  cured,  the  word  "  disease  "  being  here  used  to 
designate  that  which  causes  the  various  manifestations 
of  the  malady.  The  short  statement  that  "  syphilis  is 
an  incurable  disease,"  is  legitimate  if  we  recognize  that 
"  incurable"  means  that  there  is  no  proof  of  cure.  I 
do  not  put  this  opinion  forward  as  in  any  way  novel ; 
indeed,  I  feel  that  on  this  and  on  many  other  points  in 
these  lectures  I  express  opinions  that  are  held  by  many 
others,  some  of  which  have  been  well  stated  by  others, 

*This  statement  has  been  widely  objected,  to.  It  should  be  noted, 
however,  that  it  is  perfectly  consistent  with  the  recognition  of  the  fact 
that  the  lesions  of  syphilis  have  been  and  are  readily  removed  by 
treatment. 


108  LETTSOMIAN    LECTURES    ON  SYPHILIS 

and  all  of  which,  I  cannot  doubt,  have  been  expressed 
more  than  once.*  In  current  works  on  syphilis  the 
fact  of  incurabilit}''  is  clearly  admitted,  although  even 
in  these  it  is  not  quite  compatible  with  the  language 
here  and  there  employed.  But  the  fact  is  certainly  not 
accepted  by  the  profession  at  large  in  the  manner  that 
seems  to  me  to  be  indicated  by  the  facts.  It  is,  I  think, 
most  important,  for  practical  reasons,  that  it  should  be 
understood  by  all  that,  as  far  as  evidence  at  present 
goes — whatever  power  we  may  hope  and  anticipate 
that  the  future  will  bring — no  treatment,  however 
thorough,  will  bring  syphilis,  as  a  disease,  to  an  end,  so 
that  the  patient  does  not  suffer  again  from  any  of  its 
direct  effects.  In  this  sense  (and  it  is  the  only  proper 
sense  of  the  words)  the  assertion  seems  to  me  to  be 
open  to  no  question.  Yet  the  fact  is  very  remarkable. 
It  is  strange  that  this  should  be  true  of  a  disease  the 
effects  of  which  are  so  largely  under  control.  We  can, 
under  favorable  circumstances,  remove  most  true  spec- 
ific lesions,  we  can  bring  to  an  end  most  true  specific 
processes,  but  the  arrest  or  removal  of  the  manifesta- 
tions of  a  disease  is  a  very  different  thing  from  its  cure. 
We  can,  indeed,  do  a  little  more  than  remove  the 
manifestations  and  effects  of  the  disease  ;  we  can  restrain 


*  I  regret  that  it  has  not  been  possible  for  me  to  ascertain  the  extent  to 
which  these  and  other  opinions  have  been  before  expressed.  Hence  I  feel 
that  the  only  course  at  once  just  to  others  and  safe  for  myself  is  to  ask 
you  to  regard  nothing  in  these  lectures  as  having  any  claim  to  original- 
ity. As  I  said  at  the  outset,  my  desire  is  to  render  more  definite  the 
knowledge  that  already  exists,  and  not  to  bring  new  knowledge  into 
existence. 


AND    THE    NERVOUS    SYSTEM.  109 

the  activity  of  the  virus,  whatever  it  be,  that  causes  the 
manifestation  and  effect.  But  when  we  speak  of  the 
cure  of  a  disease  we  mean  that  its  essential  element,  the 
virus  that  lies  behind  all  its  symptoms  and  conse- 
quences, that  which  is  the  persistent  cause  beneath  the 
transient  effects — we  mean  that  this  is  made  to  cease,  is 
ended  once  and  for  all  as  a  morbific  agent,  so  that  t't 
never  again  disturbs  the  system.  In  this  sense  I 
believe  that  it  is  literally  correct  to  say  that  we  have 
no  evidence  that  syphilis  ever  is,  or  ever  has  been, 
cured. 

I  can  scarcely  doubt  that  so  absolute  a  statement 
will  seem,  even  to  some  here  to-night,  unjustified  and 
even  mistaken.  Some  of  you  may  call  to  mind  cases 
that  seem  to  contradict  it,  cases  in  which  a  patient  was 
suffering  from  symptoms  of  the  disease,  and  is  known 
to  have  been  afterward  free  from  any  indication  of  the 
malady.  Such  cases  do  occur ;  they  may  be  numerous. 
Far  more  frequent,  however,  in  the  experience  of  most 
observers,  are  cases  in  which  the  immunity  that  follows 
a  course  of  treatment  is  not  permanent,  in  which  other 
symptoms  reappear  at  a  later  period.  In  very  few  of 
the  cases  regarded  as  "  cured  "  has  the  patient  been 
kept  ilnder  observation  long  enough  to  justify  the 
positive  conclusion  that  the  disease  was  at  an  end. 
Nowhere  has  this  fact  been  recognized  more  clearly 
than  in  the  admirable  work  of  Hill  and  Cooper. 
Cases  are  common  enough  in  which  the  hope  of  cure 
produced  by  several  years  of  perfect  freedom  was 
ultimately  disappointed.  Of  the  patients  with  late 
syphilitic  lesions  that  come  under  the  observation  of 


110  LETTSOMIAN   LECTUKES    ON   SYPHILIS 

the  physician,  many,  very  many,  have  undergone 
thorough  treatment  for  the  early  symptoms.  It  is 
difficult,  I  may  say  that  to  me  it  is  impossible,  to  com- 
pare the  history  of  the  various  sufferers  from  syphilitic 
lesions,  to  compare  the  course  of  the  disease  in  cases 
in  which  treatment  was  early  and  thorough  with  those 
in  which  no  treatment  was  'employed,  and  not  to  ques- 
tion whether  early  treatment  has  yet  been  shown  to  have 
any  appreciable  influence  in  preventing  the  late  symp- 
toms of  the  disease.  But  if  this  be  so,  how  are  we  to 
explain  the  cases  in  which  the  malady  has  seemed  to 
cease  after  a  course  of  treatment,  or  those  in  which  it 
has  ceased  so  long  as  observation  has  continued  ?  I 
have  already  hinted  at  the  explanation  which  I  believe 
to  be  the  true  one.  We  saw  in  the  first  lecture  that  if 
we  compare  a  series  of  cases,  we  meet  with  many  in 
which  the  primary  affection  received  no  treatment  at 
all,  and  yet  the  later  symptoms  were  of  a  trifling 
character.  There  is  the  strongest  reason  to  believe 
that  many  other  cases  occur  in  which  late  symptoms 
are  altogether  absent.  Some  facts  that  have  an  instruc- 
tive bearing  on  this  subject  come  to  light  in  the  his- 
tories of  patients  in  the  medical  wards  of  a  hospital  or 
in  the  out-patient  room,  suffering  often  from  diseases 
that  have  no  relation  to  syphilis.  It  is  not  uncommon 
to  meet  with  those  who  have  unquestionably  suffered 
from  primary  syphilis  and  from  slight  secondary  symp- 
toms, but  who  took  little  or  no  notice  of  them,  and  who 
have  never  been  treated,  have  had  no  later  manifesta- 
tions. I  have  mentioned  the  series  supplied  to  me  by 
Dr.  Radcliffe  Crocker,  and  which  I  hope  he  will  extend 


AND    THE    NERVOUS    SYSTEM.  Ill 

and  publish,  for  their  importance  is  very  great.  In  this 
series  there  are  many  cases  in  which  notable  late  syph- 
ilitic skin  eruptions  occurred  without  any  recognized 
previous  manifestations  of  the  disease,  and  even  many 
in  which  the  primary  lesion  had  been  unnoticed  by  the 
patient,  and  was  certainly  never  treated.  As  I  have 
said,  there  must  be  many  more  with  a  similar  latency 
of  the  early  stages,  with  a  similar  absence  of  treatment, 
who  passed,  not  merely  six  or  ten  years  without  any- 
thing to  call  the  malady  to  notice,  but  who  never 
observed,  through  life,  any  manifestation  of  the  disease 
to  tell  them  that  they  were  or  had  been  its  subject. 
Take,  again,  the  other  class  of  cases  I  referred  to- — the 
immunity  of  mothers  of  syphilitic  children.  They  are 
certainly  syphilitic,  and  yet  many  of  them  have  never 
been  treated  and  never  suffer.  I  believe  that  the 
variations  in  the  general  course  of  the  disease,  in  those 
who  have  been  treated,  find  parallels  in  the  course  of 
cases  that  have  not  been  treated.  I  suspect  that  if  a 
large  number  of  each  class  could  be  compared  the  dis- 
crepancy between  the  two  series  would  be  found  to  be 
surprisingly  small,  and  that  it  would  not  be  difficult  to 
find  in  each  series  a  corresponding  proportion  of  cases, 
on  the  one  hand,  in  which  the  disease  without  treat- 
ment was  brief  and  trifling,  and,  on  the  other  hand,  in 
which  the  disease  with  treatment  was  prolonged  and 
severe.  All  the  facts,  impartially  examined,  seem  to 
me  to  have  one  meaning,  clear  and  unmistakable  to 
those  who  choose  to  read  it.  The  extreme  variations 
in  the  natural  character  and  course  of  the  disease  have 
not  been  sufficiently  considered  and  allowed  for  by 


112  LETTSOMIAN   LECTURES   ON   SYPHILIS 

those  who  are  under  the  impression  that  the  cure  of 
syphilis  is  certainly  within  our  power.  This  impres- 
sion is  an  illusion  produced  by  variations  in  the  course 
of  the  disease.  In  some  patients  the  disease  is  brief; 
the  symptoms  that  bring  the  patient  under  treatment 
may  be  the  expiring  effort  of  the  virus,  and  the  spon- 
taneous cessation  of  the  disease  is  ascribed  to  the  treat- 
ment which  was  adopted.  In  other  cases  the  tendency 
to  further  manifestations,  at  some  future  time,  near  or 
distant,  may  be  so  strong  that  in  spite  of  the  most 
energetic  treatment,  long  continued,  many  times 
repeated,  wave  after  wave  of  activity  brings  to  the 
unhappy  subject  year  after  year  of  varied  suffering, 
and  sometimes  his  life  ends  before  the  disease. 

I  have  put  the  matter  strongly  in  order  to  empha- 
size the  essential  truth.  But  certain  qualifications  are 
desirable,  although  they  do  not  touch  the  fact  itself. 
One  qualification  is  that  while  we  have  no  proof  that 
we  ever  can  or  ever  have  cured  syphilis,  it  is  possible 
that  we  do  come  very  near  the  achievement,  and  even 
sometimes  attain  it.  I  said  that  some  manifestations 
are  probably — indeed,  I  might  say  certainly — the  ex- 
piring efforts  of  the  malady.  It  may  be  that  in  some 
others  the  symptoms  that  bring  the  patient  under 
treatment  are  only  the  penultimate  manifestations,  and 
that  some  further  consequences,  which  would  occur 
were  it  not  for  the  treatment,  may  be  averted.  Then 
we  do  arrest  the  symptoms  altogether.  In  such  a  case 
the  malady  may  be  said  to  be  cured  ;  but  the  cure  is  at 
best  limited,  and  cannot  be  regarded  as  more  than 
hypothetical.  The  second  reservation  is  one  rather  of 


AND    THE    NERVOUS    SYSTEM.  113 

words  and  theory  than  of  fact.  There  are  some  who 
hold  that  the  duration  of  the  disease  is  much  more 
brief  than  that  of  its  manifestations,  that  these  later 
symptoms  are  indirect  consequences,  either  in  their 
mode  of  production  or  in  the  mechanism  by  which 
they  are  caused.  The  statement  I  have  made  is  one 
that  is  independent  alike  of  pathology  that  is  known 
or  any  theory  that  may  be  held.  Whatever  be  the  in- 
timate and  ultimate  pathology  of  the  later  symptoms 
from  the  point  of  view  of  practical  medicine,  they  are 
part  of  the  disease,  and  no  question  as  to  their  origin 
or  their  relation  to  the  virus  can  alter  the  fact  that  the 
disease,  as  a  disease  to  be  dealt  with,  and  not  merely  to 
be  thought  about,  is  not,  in  the  proper  sense  of  the 
word,  a  disease  that  can  be  cured.  Speculations  as  to 
the  origin  of  the  lesions,  and  the  essential  nature  of  the 
malady  at  different  periods,  have  no  influence,  it  seems 
to  me,  on  the  practical  problems  to  which  we  must  now 
confine  our  attention,  although  it  may  be  that  these 
practical  questions  have  an  important  bearing  on  these 
speculations.  Although  the  course  of  the  disease  in 
its  relation  to  treatment  justifies  the  doubt  whether  it  is 
ever  cured,  except  in  this  narrow  and  partial  sense,  the 
question  arises  whether  the  removal  of  the  lesions,  and 
the  repression  of  the  activity  of  the  essential  elements 
of  the  disease,  have  an  influence  on  the  course  of  the 
affection.  It  is  difficult  here  to  resist  the  seductive 
attractions  of  theory  and  of  analogy.  But  the  ques- 
tion can  be  answered  only  by  facts,  and  we  ought  not 
to  try  to  obtain  the  semblance  of  an  answer  in  any 
other  way. 


114  LETTSOMIAN   LECTURES    ON   SYPHILIS 

The  conclusion  that  the  essential  element  in  the  dis- 
ease resists  treatment,  and  runs  its  course  uninfluenced 
by  our  efforts,  is  in  harmony  with  what  we  know  of 
other  specific  diseases  due  to  a  poison  introduced  from 
without  and  communicable  from  one  person  to  another. 
There  is  not  any  fact  whatever  to  show  that  a  single 
disease  of  this  kind  can  be  cut  short.  The  course  of 
the  acute  exanthemata  cannot  be  arrested  by  any 
means  at  our  disposal  at  any  stage  of  their  course,  and 
the  same  seems  true  of  this  chronic  exanthematous 
disease.  This  is  eminently  true  also  of  the  disease  that 
stands  perhaps  nearer  to  syphilis  than  any  other  known 
malady — leprosy. 

Here  we  catch  another  glimpse  of  the  strange  duality 
of  the  disease.  And  yet  the  word  "  strange  "  is  scarce!}' 
accurate.  In  syphilis  we  probably  only  see  that  which 
exists  in  all  maladies  of  like  nature,  but  in  most  others, 
to  a  large  extent,  escapes  our  notice.  What  is  it  that 
treatment  influences  in  so  remarkable  a  manner? 
What  is  it  that  remains  in  spite  of  the  treatment — 
remains,  to  assume  from  time  to  time  a  fresh  activity, 
and  to  cause  renewed  manifestations?  We  say,  in 
general  terms,  that  treatment  removes  the  effects  of  the 
disease,  the  local  lesions  it  produces.  Besides  this, 
treatment  seems  to  be  capable  of  repressing,  and  even 
suppressing,  the  activity  of  the  materies  morbi.  Take 
this  one  fact,  evidence  of  which  you  will  find  presented 
with  care  in  the  work  of  Hill  and  Cooper :  A  syphilitic 
woman  who  would  bear  a  child  certainly  diseased,  and 
probably  dead,  can  by  treatment  be  made  to  bear  a 
child  that  at  the  time  of  birth  shows  no  trace  of  the 


AND   THE   NERVOUS   SYSTEM.  115 

disease ;  yet  even  such  an  influence  on  the  morbid  pro- 
cess in  the  mother  does  not  prevent  her  from  again 
suffering.  If  we  are  able  to  hold  securely  the  outline 
of  a  general  truth  only  by  means  of  the  point  of  an 
hypothesis,  we  may  consider  that  our  drugs  destroy  the 
developed  and  developing  organisms,  and  fail  to  influ- 
ence the  germs  of  these.  But  much  remains  obscure, 
when  this  or  any  other  hypothesis  that  we  can  frame 
has  done  the  utmost  that  it  can  to  clear  our  view,  and 
we  must  wait,  perhaps  for  long,  before  we  can  under- 
stand the  real  reason  why  we  are  able  to  do  so  much, 
and  yet  can  do  no  more. 

The  general  treatment  of  syphilitic  lesions  does  not 
come  within  the  limits  that  I  have  set  to  these  lectures, 
and  even  if  time  permitted  me  to  make  an  exception  on 
account  of  the  importance  of  the  subject,  I  should  still 
hesitate  to  take  up  your  time  with  that  which  every 
student  is  taught.  The  few  minutes  that  remain  I 
may  best  spend  in  pointing  out  certain  points  on  which 
we  need  to  have  a  far  firmer  foundation  of  observed 
facts  than  has  at  present  been  supplied. 

One  question  on  which  there  is  some  difference  of 
opinion  is  regarding  the  respective  power  of  mercury 
and  of  iodide  of  potassium,  which  is  represented  in  its 
extreme  forms  by  the  custom  of  some  physicians  to 
give  only  iodide  for  the  late  lesions,  and  the  opinion  of 
others  that  mercury  alone  is  effective,  and  that  iodide 
has  only  the  power  of  bringing  into  an  efficient  activity 
the  mercury  that  may  have  been  deposited  and  held 
inert  in  the  various  tissues.  The  only  point  chiefly  at 
issue,  then,  is  the  influence  of  iodide.  I  have  on  this 


116  LETTSOMIAN    LECTURES   ON   SYPHILIS 

subject  to  range  myself  with  the  majority.  It  seems  to 
me  impossible  to  see  much  of  the  true  specific  lesions 
of  the  nervous  system,  and  not  to  believe  that  over 
most  of  them  iodide  has  a  powerful  influence.  The 
symptoms  of  a  gumma,  for  instance,  lessen  and  pass 
away  under  the  influence  of  iodide  of  potassium  as 
speedily  and  as  completely  as  would  seem,  d,  priori,  to 
be  possible  with  any  agent.  I  am  inclined  to  think 
that  when  a  lesion  is  distinctly  influenced  by  either 
drug,  if  this  is  given  freely,  the  effect  of  one  is  as  great 
as  that  of  the  other ;  and  in  most  circumstances  I  doubt 
whether  it  is  necessary  to  follow  the  iodide  with  a  course 
of  mercury.  But  this  is  only  an  impression.  The 
physician  cannot  gain  from  his  cases  any  really  trust- 
worthy conviction.  We  need  more  detailed  observations 
by  those  under  whose  observation  the  treatment  of 
lesions  in  the  skin  and  other  parts  can  be  seen  ;  we 
need  observations,  superfluous  for  them  but  most 
important  for  us,  as  to  the  relative  effect  of  different 
kinds  of  treatment,  and  the  time  needed  for  the  com- 
plete removal  of  specific  processes.  And  we  need,  in 
such  observations,  careful  discrimination,  as  far  as  is 
possible,  between  the  actual  effect  of  the  drug  and  the 
changes  which  result  from  that  effect,  but  need  time  for 
their  full  completion.  It  is  very  easy  for  physicians  to 
mistake  the  remote  effect  of  the  treatment,  the  slow 
improvement  in  symptoms  that  goes  on  for  a  consider- 
able time  after  the  syphilitic  lesion  has  been  removed, 
for  the  slow  removal  of  this  lesion. 

At  the  same  time  the  question  needs  asking,  and  needs 
an  answer :   Are  there  late  syphilitic  lesions  over  which 


AND    THE    NERVOUS    SYSTEM.  117 

iodide  of  potassium  has  no  influence,  and  which 
yield  to  mercury  ?  Some  years  ago  this  question  was 
impressed  upon  me  by  the  case  of  a  woman  who  had  a 
firm  mass  deeply  seated  in  the  posterior  triangle  of  the 
neck,  compressing  the  lower  nerve  roots  entering  the 
brachial  plexus,  and  causing  paralysis  of  the  muscles 
of  the  forearm  and  hand.  She  presented  unmistakable 
signs  of  constitutional  syphilis,  including  the  loss  of 
almost  the  whole  of  the  soft  palate,  which  had  been 
destroyed  by  ulceration  several  years  before.  Iodide  of 
potassium  was  given  in  large  doses  for  about  six  weeks, 
but  without  the  slightest  effect  on  the  mass.  Perhaps 
during  the  following  two  months  it  did  not  get  larger, 
but  it  certainly  did  not  get  less,  nor  did  the  pain  which 
was  caused  by  the  compression  of  the  nerve  roots. 
Mercury  was  then  given,  and  as  soon  as  its  influence 
was  established  the  mass  began  to  lessen  and  the  pain 
ceased,  and  in  a  few  weeks  the  neck  had  resumed  a 
normal  state.  The  lesion  was  no  doubt  the  chronic 
syphilitic  periadenitis  not  uncommon  in  this  region. 
Except  for  one  possible  source  of  fallacy  (to  be  men- 
tioned later),  this  case  seems  to  be  conclusive  evidence 
of  the  possibility  of  this  difference. 

I  have  not  met  with  any  case  of  intra-cranial  disease 
in  which  there  was  reason  to  believe  that  mercury  was 
successful  while  iodide  failed.  In  the  case  of  gummata 
I  have  found,  as  a  rule,  the  effect  of  iodide  perfectly  sat- 
isfactory, as  great  as  seemed  possible,  and  with  entire 
removal  of  the  symptoms,  except  in  cases  in  which 
such  complete  removal  could  not  be  expected.  Syphilitic 
inflammation  is,  I  think,  better  treated  with  mercury, 


118  LETTSOMIAN    LECTURES   ON   SYPHILIS 

since  this  has  far  more  influence  than  iodide  over  the 
process  of  inflammation,  irrespective  of  its  nature  and 
cause,  but  I  cannot  say  that  this  opinion  is  based  on 
observations  free  from  sources  of  fallacy. 

With  regard  to  the  methods  of  administration  of 
mercury  I  have  nothing  to  say.  The  old  method  of 
inunction  seems  to  me  to  bring  the  patient  under  the 
influence  of  the  drug  as  speedily  as  it  can  be  done  with 
safety,  and  with  a  certainty  incomparably  greater  than 
the  administration  by  the  mouth.  I  have  been  deterred 
from  a  trial  of  the  hypodermic  method  because  the 
published  evidence  seemed  to  me  not  to  afford  any 
satisfactory  proof  of  superiority,  being  destitute  of  the 
element  of  comparison  essential  to  such  proof,  and 
because  this  method  seems  to  afford  an  opportunity  for 
psychical  influence  not  free  from  risk  of  that  which  is 
undesirable.  But  I  would  not  for  one  moment  suggest 
that  such  an  influence  has  entered  into  the  motives  of 
those  who  have  used  this  method. 

There  are  two  points  in  the  treatment  of  syphilitic 
diseases  of  the  nervous  system  on  which  I  think  a 
word  of  caution  is  urgently  needed.  The  first  is  re- 
garding the  prolonged  administration  of  anti-syphilitic 
drugs,  especially  of  iodide  of  potassium.  By  "pro- 
longed "  I  mean  exceeding  from  six  to  ten  weeks. 
I  believe  that  full  doses  in  this  time  will  effect  all 
that  can  be  thus  achieved  in  the  removal  of  the 
syphilitic  process.  But  here,  as  I  have  just  said, 
we  want  facts  that  are  visible — numerous  and  care- 
fully observed — to  guide  us  in  our  conclusion.  I 
do  not  say  that  the  symptoms  will  have  disappeared. 


AND    THE    NERVOUS   SYSTEM.  119 

It  cannot  be  too  firmly  remembered  that  symptoms 
are  due  to  changes  that  are  not  syphilitic — changes 
in  the  nerve  elements  secondary  to  the  syphilitic  dis- 
ease, but  so  far  independent  in  course  that  they  may 
persist  long  after  the  specific  lesion  is  at  an  end. 
Hence,  the  fact  that  the  symptoms  have  not  yet 
ceased  is  no  indication  that  the  specific  lesion  is  not 
entirely  removed.  Here,  then,  I  would  range  myself 
with  the  minority — a  minority  fast  growing  in  size, 
especially  in  Germany — with  those  who  hold  that 
the  long-continued  treatment  by  small  doses  of  mer- 
cury or  iodide  is  a  mistake,  great  and  dangerous; 
who  hold  that  treatment  of  any  true  specific  lesion 
should  be  energetic,  but  should  continue  only  a  little 
longer  than  is  necessary  to  remove  the  lesion,  repeated, 
it  may  be,  after  an  interval  occupied  either  by  tonic 
treatment  or  by  the  other  of  the  two  chief  drugs. 
If  iodide  is  continued,  as  it  often  is,  during  many 
months  (and  much  more,  as  it  sometimes  is,  during 
years),  there  is  a  danger  that  the  system  and  tissues 
'of  the  patient  may  become  so  accustomed  to  its  pres- 
ence that  the  drug  will  no  longer  hold  in  check  the 
syphilitic  processes.  Probably  we  may  still  influence 
the  lesions  by  increasing  the  dose,  but  this  process 
must  have  limits,  in  practice  if  not  in  theory.  Such 
prolonged  and  augmented  treatment  may  do  definite 
injury  to  the  patient's  health,  and  even  then  may 
fail  to  effect  the  desired  object.  If  the  poison  is  an 
organized  virus  we  might  ci  priori  expect  this  result. 
By  long-continued  gradual  alteration  in  the  condi- 
tions, low  organisms,  as  Dallinger  has  shown  in  his 


120  LETTSOMIAN   LECTURES   ON   SYPHILIS 

remarkable  experiments,  can  be  made  to  endure  influ- 
ences that  would  at  first  be  fatal  to  them.  By  slowly 
raising  the  temperature,  they  will  not  only  live,  but 
will  flourish,  at  a  degree  of  heat  which,  had  it  not 
been  for  their  acclimatization,  would  kill  them  in 
a  few  minutes.  Still,  the  question  is  not  one  in 
which  we  can  be  guided  by  theory,  far  less  by  an 
analogy  possibly  remote.  There  is,  however,  a  posi- 
tive danger  in  this  method,  and  it  is  especially  great 
in  the  practice  to  which  I  referred  at  the  beginning  of 
the  lecture,  that  of  repeated  courses  of  energetic  treat- 
ment to  remove  residual  symptoms  that  cannot  be 
thus  removed,  because  they  do  not  depend  on  any 
residual  specific  process.  The  test  of  experience  alone 
can  show  the  extent  of  this  danger,  but,  at  the  same 
time,  the  fact  does  not  need  for  its  proof  the  evidence 
of  accumulated  experience  or  numerous  observations. 
A  single  clear  instance  will  suffice  to  establish  it, 
and  no  number  of  negative  instances  would  dis- 
prove it.  We  know  how  erratic  the  course  of  syphi- 
lis is,  and  how  great  must  be  the  variations  in  the 
state  and  tendency  of  the  virus  in  the  system.  In 
one  case,  if  the  energy  of  the  disease  is  subdued, 
it  is  for  a  long  time  tranquil,  while  in  another  the 
tendency  to  fresh  development  soon  reasserts  itself. 
Hence  it  may  readily  happen  that  a  series  of  cases 
leads  to  a  delusive  confidence  in  the  safety  of  a 
course  of  treatment,  which  is,  nevertheless,  now  and 
then  fraught  with  danger. 

The    following    instance    clearly  proves    that    the 
danger  is  not  imaginary.     Many  years   ago   a  man 


AND   THE   NERVOUS    SYSTEM.  121 

came  under  my  treatment  with  symptoms  of  local 
chronic  meningitis  about  the  pons.  Ten  grains  of 
iodide  of  potassium  were  given,  and  the  symptoms 
rapidly  lessened.  Slight  residual  symptoms,  however, 
remained,  for  which  iodide  was  continued,  and  he  took 
it  regularly  for  about  four  months.  At  the  end  of  that 
time  some  obscure  cerebral  symptoms  developed,  the 
syphilitic  nature  of  which  was  doubted  because  they 
had  developed  in  spite  of  the  iodide.  He  was  ad- 
mitted to  the  hospital,  and  the  iodide  was  continued 
and  slightly  increased,  but  the  symptoms  rapidly  de- 
veloped, spinal  symptoms  were  superadded,  and  in  a 
few  weeks  he  died.  Post-mortem  we  found  the  remains 
of  local  syphilitic  meningitis  at  the  base,  as  had  been 
suspected,  and  also  a  second  syphilitic  gumma  in 
the  cerebral  hemisphere,  and  another  in  the  spinal 
cord.  Here,  then,  we  had  clearly  a  new  development 
of  that  syphilitic  lesion  over  which  iodide  has  most 
influence,  although  the  patient  was  at  the  time,  and 
had  been  for  long  before,  continuously  taking  the  drug. 
I  have  seen  similar  instances,  both  with  iodide  and 
mercury,  but  this  case  impressed  me  so  as  to  preclude 
the  occurrence  of  fresh  illustrations  in  my  own  practice, 
and  I  do  not  care  to  adduce  evidence  not  observed  by 
myself  throughout.  Especially  in  early  syphilis,  how- 
ever, I  have  been  satisfied  that  the  virus  may  resume 
activity  during  the  continuation  of  mild  mercurial 
treatment.  Here  there  is  a  source  of  a  possible  fallacy 
in  the  case  I  mentioned  just  now,  in  which  iodide  had 
no  influence  on  the  syphilitic  process  in  the  neck.  It 
is  possible  that  the  patient  had  been  taking  iodide  for 
11 


122  LETTSOMIAN    LECTURES   ON   SYPHILIS 

a  long  time  before  she  came  under  my  care.  There  is 
no  evidence  of  it,  but  the  point  was  not  investigated, 
and  must  remain  doubtful. 

I  would  add  only  one  other  remark.  If  it  is  true 
that  we  cannot  cure  syphilis,  it  is  most  important  to 
consider  how  it  can  best  be  kept  in  check.  This  is 
why  the  fact  of  incurability,  if  true,  is  so  important. 
A  mistaken  belief  in  curability  may  dangerously  hin- 
der attempts  at  prevention.  If  no  present  treatment 
can  prevent  future  development,  then  it  is  wise,  whether 
they  come  or  not,  to  anticipate  them.  I  think  the  cus- 
tom sometimes  recommended  is  good — that  every 
syphilitic  subject,  for  at  least  five  years  after  the  date 
of  his  last  symptoms,  should  have  a  three  weeks'  course 
of  treatment  twice  every  year,  taking  for  that  time 
twenty  or  thirty  grains  of  iodide  a  day.  If  this  practice 
were  adopted  generally,  is  it  not  reasonable  to  antici- 
pate that  grave  lesions  would  be  much  more  rare  ? 

The  idea  that  residual  symptoms  are  necessarily 
proof  of  residual  specific  lesions,  which  can  be  removed 
by  a  renewal  of  treatment  that  has  already  been  ener- 
getic, is  not  only  destitute  of  proof,  but  is,  as  I  have 
said,  dangerous.  I  have  alluded  already  to  the  ease 
with  which  a  mistaken  conclusion  can  be  reached. 
The  danger  depends  on  the  tendency  which  I  have 
more  than  once  mentioned,  and  must  again  advert  to 
in  its  therapeutical  aspect — the  tendency  to  degenera- 
tive changes  in  the  nervous  system,  presented  so  fre- 
quently by  those  who  have  had  syphilis.  The  danger 
is  considerable  both  in  those  who  have  had  true  syphi- 
litic lesions  and  in  those  who  have  not.  These  degen- 


AND   THE    NERVOUS   SYSTEM.  123 

erations,  as  we  have  seen,  are  not  checked  by  specific 
treatment,  and  there  is  some  reason  to  think  that  they 
are  not  rarely  accelerated  by  such  treatment,  especially 
when  it  exerts  a  depressing  influence  on  the  general 
health.  I  have  seen  many  instances  of  this,  especially 
from  energetic  mercurial  treatment.  In  most  cases  of 
the  kind,  the  evil  has  been  done  by  the  repetition  of 
mercurial  treatment,  in  the  hope  of  removing  symp- 
toms which  were  not,  and  could  not  be,  removed  by 
such  treatment. 

There  is  one  other  important  element  in  the  treatment 
of  luetic  lesions  in  the  nervous  system  that  is  often  for- 
gotten. We  have  to  do  with  a  syphilitic  process,  and 
with  the  damage  to  the  nerve  tissues  which  the  process 
causes.  Thus  there  are  three  elements  in  the  affection 
— the  specific  process,  the  damage  to  the  nerve  tissues 
caused  by  that  process,  and  the  symptoms  that  are 
due  to  this.  It  is  important  to  recognize  each  of 
these  elements,  and  to  consider,  in  arranging  our 
treatment,  how  far  the  two  pathological  elements  need 
special  measures.  In  arranging  the  treatment  of  syphi- 
litic lesions  we  must  never  forget,  any  more  than 
in  diagnosis  and  prognosis,  the  simple  changes  in  the 
nerve  tissues  on  which  alone  the  symptoms  depend.  To 
confine  our  attention  to  the  syphilitic  element  in  treat- 
ment is  to  neglect  measures  that  may  make  an  appre- 
ciable difference  in  the  ultimate  result.  The  cases  are, 
it  is  true,  rare  in  which  we  are  able  to  appreciate  the 
effect  of  neglect  on  the  one  hand,  or  of  recognition  on 
the  other.  In  the  improvement  that  follows  the  re- 
moval of  the  syphilitic  process,  we  are  commonly  unable 


124  LETTSOMIAN   LECTURES   ON   SYPHILIS 

to  discern  that  which  may  be  due  to  collateral  measures. 
A  chief  bane  of  modern  therapeutics  is,  it  seems  to  me, 
the  demand  for  proof  where  proof  cannot  be  forthcom- 
ing, and  the  tendency  to  reject  that  of  which  the 
evidence  is  not  clear,  when  the  absence  of  such  evi- 
dence is  often  no  ground  for  inferring  the  absence  of 
benefit.  In  every  case,  all  measures  should  be  em- 
ployed that  are  suggested  by  what  we  can  learn  of  the 
nature  of  the  morbid  process  and  of  the  known  ten- 
dency of  therapeutic  agents,  in  confidence  that  they 
cannot  be  altogether  without  influence  in  bringing 
about  the  ultimate  result,  and  satisfied  if  now  and  then 
we  can  distinctly  trace  their  beneficial  action. 

Here  I  must  end.  To  me,  and  if  I  have  been  in 
any  measure  successful  in  achieving  the  result  that 
has  been  my  aim,  to  you  also,  the  subject  cannot  but 
grow  in  importance  the  more  it  is  studied ;  its  vast  pro- 
portions seem  to  loom  still  vaster,  through  the  mists 
that  obscure  its  features  and  prevent  clear  vision  of  its 
outline — still  to  us  unlimited.  To  those  who  have 
attempted  to  explore  the  range  of  its  influence  on  the 
nervous  system,  or  to  those  who  look  on  and  note  the 
efforts  of  others — who  see,  from  time  to  time,  some 
fresh  discovery  extend  our  knowledge  in  directions 
altogether  unsuspected,  and  see  region  after  region  of 
disease  opened  out  before  the  mental  eye  as  part  of  this 
affection — the  malady  may  seem  like  some  "  dark  con- 
tinent," not  yet  half  traversed,  in  which  the  known 
may  even  now  be  less  than  the  unknown.  But  the 
nervous  system  is  only  one  out  of  many  parts  of  the 


AND    THE    NERVOUS   SYSTEM.  125 

human  frame  in  which  this  terrible  disease  plays 
,  havoc,  and  it  may  be  that  the  greater  frequency  and 
extent  of  its  influence  here  is  merely  apparent,  due  to 
the  readiness  with  which  these  delicate  structures  are 
deranged  in  their  structure  and  function,  and  of  the 
distinctness  with  which  such  derangement  is  revealed. 
Strange  indeed  it  is  to  think  that  all  this  train  of  mor- 
bid processes — so  long,  so  varied,  often  so  disastrous — is 
the  consequence  of  the  entrance  into  the  system  of  a 
few  organisms,  scarcely  to  be  seen  even  with  the  utmost 
increase  in  the  power  of  vision  that  human  ingenuity 
has  yet  contrived.  And  strange  is  it  to  think  that  this 
malady,  rivaled  in  its  total  capacity  for  wrecking 
human  happiness,  and  health,  and  life,  by  no  other, 
and  exceeded  in  apparent  dreadfulness  only  by  those 
whose  effects  are  more  sudden,  is  equally  formidable 
by  reason  of  our  limited  power  over  it.  Make  what 
deductions  you  can  for  the  mild  or  latent  forms  of  the 
disease,  and  for  our  power  of  repression,  the  fact  remains 
that  we  have  yet  to  find  the  means  of  arresting  it ;  and, 
I  may  add,  we  have  yet  to  find  effective  means  for  its 
prevention.  That  philanthropy,  the  vision  of  which  is 
so  narrowed  by  misplaced  feeling  that  only  one  imper- 
fect aspect  of  the  means  employed  can  be  perceived, 
has  decreed  that  the  chief  method  hitherto  suggested 
shall  not  have  even  a  trial  under  fair  conditions,  and, 
despite  the  manifold  benefit  from  its  partial  use,  has 
decreed  that  the  malady  shall  continue  to  work  its  ruin 
on  the  innocent  and  the  guilty  alike.  One  means 
alone  remains,  old  as  the  malady  itself,  by  which  it 
can  be  prevented.  One  method,  and  one  alone,  is 


126  LETTSOMIAN    LECTURES    ON    SYPHILIS 

possible,  is  sure,  and  that  one  is  open  to  all.  It  is  the 
certain  prevention  secured  by  unbroken  chastity.  Is 
this  potentiality  increasing?  As  we  look  back  through 
the  long  centuries,  we  see  the  sensual  more  and  more 
dominant  as  we  recede,  and  clearly  lessening  as  we 
return  toward  the  present.  But  when  we  look  around, 
we  can  trace  small  ground  for  hope  that  the  disease 
will  thus  be  materially  reduced,  unless  or  until  there 
is  some  change  in  men  more  potent  and  effective 
than  the  slow  "  live  upward,  working  out  the  beast " 
of  moral  evolution.  But  that  which,  perhaps,  may  not 
be  for  the  mass  may  yet  be  for  the  individual.  And, 
in  ending,  I  must  ask  a  question  that  I  would  fain  had 
left  unasked,  unthought.  Do  we  do  all  we  can — and 
our  profession  gives  us  power  that  no  other  has — do  we 
do  all  we  can  to  promote  that  perfect  chastity  which 
alone  can  save  from  this  and  from  that  which  is  worse  ? 
The  opinions  that,  on  pseudo-physiological  grounds, 
suggest  or  permit  unchastity  are  absolutely  false. 
Trace  them  to  their  ultimate  basis,  and  they  are 
groundless.  They  rest  only  on  sensory  illusions,  one 
of  the  many  illustrations  of  a  maxim  I  have  often  to 
impress  on  various  sufferers,  "  There  are  no  liars  like 
our  own  sensations."  Rather,  I  should  say,  they  rest 
on  misinterpretations  of  these,  always  biased,  and 
often  deliberate.  With  all  the  force  that  any  knowl- 
edge I  possess,  and  any  authority  I  have,  can  give, 
I  assert  that  no  man  ever  yet  was  in  the  slightest 
degree  or  way  the  worse  for  continence  or  better  for 
incontinence.  From  the  latter  all  are  worse  morally ; 
a  clear  majority  are  worse  physically ;  and  in  no  small 


AND    THE    NERVOUS   SYSTEM.  127 

number  the  result  is,  and  ever  will  be,  utter  physical 
shipwreck  on  one  of  the  many  rocks,  sharp,  jagged- 
edged,  which  beset  the  way,  or  on  one  of  the  many 
banks  of  festering  slime  which  no  care  can  possibly 
avoid.  Let  us,  then,  with  our  power  for  good  or  evil, 
beware  lest  we  ever  give  even  a  silent  sanction  to  that 
against  which,  I  am  sure,  on  even  the  lowest  grounds 
that  we  can  take,  we  should  resolutely  set  our  face  and 
raise  our  voice. 


INDEX. 


A. 

Analysis  of  fifty  cases  of  syphi- 
litic disease  of  the  cerebral 
arteries,  71,  el  seq. 

Aneurism,  intracranial,  syphilitic 
and  non-syphilitic,  19,  20. 

Arterial  disease,  syphilitic,  seat 
of,  18-21. 

Atheroma,  difference  between  it, 
and  correspondence  in  seat  with 
it,  and  syphilitic  arterial  dis- 
ease, 18,  19. 

Atrophy,  chronic  muscular,  rela- 
tion of,  to  syphilis,  50. 

B. 

Barlow,  reference  to,  24. 
Broaclbent,  reference  to,  10. 
Buzzard,  reference  to,  10. 

C. 

Cerebral  embolism,  70,  77-78. 
hemorrhage,  due  to  syphilitic 

vascular  disease,  21. 
meningitis,  chronic,  local,  of 
luetic  origin,    symptomat- 
ology and  diagnosis  of,  67- 
68. 
thrombosis,  results  of,  69,  70, 

and  78. 
premonitory     symptoms 

in,  76-77. 

Cerebritis,  pathologically  specific, 
rare,  22. 


Charcot  and  Gombault,  reference 
to,  22,  40. 

Chastity,  unbroken,  a  certain  pre- 
vention against  syphilis,  126. 

Convulsions,  significance  of 
absence  of,  attending  onset  of 
hemiplegia  due  to  a  cortical 
lesion,  72. 

Cranial  neuritis,  syphilitic,  prog- 
nosis of,  105. 

D. 

Dallinger,  reference  to,  109. 
Diagnosis  of  syphilitic  disease  of 

the  nervous  system,  outline  of 

process,  56-65. 
Diphtheria  and  syphilis,  analogy 

between  the  effects  of,  52. 

E. 

Evidence,  question  of,  as  an  aid 
to  the  diagnosis  of  non- 
pathologically  s  p  e  c  i  f  i  c 
luetic  lesions,  25. 

of  sequence  as  proof  of  causa- 
tion, 25-32 

of  treatment  as  proof  of  causa- 
tion, 25,  36. 

F. 

Functional  nervous  disorders,  the 
origin  of  improperly  attributed 
to  syphilis,  55-56. 


129 


130 


INDEX. 


G. 

Gummata,  common  situation  of 
growth  of,  18. 

general  and  special  symptom- 
atology and  diagnosis  of 
65. 

special  prognosis  of,  104. 


H. 

Heubuer,  reference  to,  68. 

Hemiplegia,  sudden,  not  due  to 
embolism  or, injury,  occurring 
between  25  and  45  years,  prob- 
ably luetic,  77-78. 

Hill,  Berkley,  reference  to,  30. 
and  Cooper,  reference  to,  109, 
114. 

Hutchinson,  Jonathan,  reference 
to,  33,  48. 


I. 

Infiltrating  growths,  prognosis  of, 

105. 
Iodides  and  mercury,   respective 

power  of,  in  the   treatment  of 

syphilis.  115-117. 
Irritation,  prognosis  of  symptoms 

of,  105-106. 


J- 

Julliard  and  Pierret,  reference  to, 
24. 

K. 

Kahler,  reference  to,  24. 


L. 

Latent  syphilis,  frequency  of,  34- 

35. 

Law,  Colles's,  35. 
Luetic    lesijns,   division  of  into 

specific  and  non-special,  16-17. 


"Luetic,"  the  term  preferable 
to  "specific,"  when  used  as  a 
synonym  for  "  syphilitic,"  18. 


M. 

Meningitis,  chronic  syphilitic,  37. 
prognosis  of  all  forms  of,  104. 
Mercury   and   the     iodides,   pro- 
longed treatment  by, 
dangerous,  118,  119. 
respective  power  of,  in 
the  treatment  of  svphi- 
lis,  115-117. 
Myelitis,  disseminated,  subacute, 

24. 
pathologically   specific   rare, 

22. 

relation   of,  to   syphilis,  39- 
41. 

N. 

Narcotic  cerebral  softening  from 

syphilitic  arterial  disease,  69, 

103. 
Neuritis,    cranial,    pathologically 

specific,  23. 
Nuclear  palsy,  characteristics  of, 

87. 

O. 

Ocular  palsies,  relation  of,  to  syph- 
ilis, 46-48. 
Optic  neuritis,    due  to    syphilo- 

mata,  66-67. 
in  the  diagnosis  of  syphi- 
litic lesions,  56. 

P. 

Pachymeningitis,  cerebral,  22. 

spinal,  22. 

Paralysis,  acute  ascending,   rela- 
tion of,  to  syphilis,  41. 
cerebral,    syphilitic,     symp- 
toms attending  onset 
of,  73-74. 


INDEX. 


131 


Paralysis,  due  to  specific  cerebral 
arterial    disease,  variation 
in  degree  of,  73-74. 
general,  of  the  insane,  hemi- 

plegia  in,  83-84. 
relation   of,  to  syphilis, 

49-50,  83-84. 
Pathology,  ultimate,  of  syphilis, 

12,  51-54. 
Percentage  of    males   who   have 

had  syphilis,  29-32,  35. 
Prognosis  of  luetic  disease  of  the 
nervous  system,  essential  prin 
ciples  underlying  it,  95-104. 

R. 

Reason  for  lack  of  diagnostic  sig- 
nificance of  result  of  treatment 
in  syphilitic  cerebral  throm- 
bosis, 7."). 

S. 

Sclerosis,  focal,  of  nerve-centres, 

relation  to  syphilis,  42. 
Sequence,    isolated   instances   of, 

no  proof  of  causation,  26-27. 
' '  Specific ' '      lesions,     character, 
situations  and  effects,  18- 
19. 

wrongly  used  as  euphemism 
for  "syphilitic,"  17-18. 


Strlimpell's  hypothesis,  53. 

Sylviau  artery,  that  by  which 
arterial  disease  causes  symp- 
toms, 73. 

Syphilis  an  incurable  disease,  107- 

109. 

ultimate  pathology  of,  12,  51- 
54. 

Syhilitic  processes  affecting  the 
nervous  system,  symptomat- 
ology and  diagnosis  of,  65  et  seq. 

Syphilomata,  diagnostic  value  of, 
effects  of  treatment  on,  67. 

System  degenerations,  relation  of, 
to  syphilis,  44-46. 


T. 

Tabes  dorsalis,  relation  of,  to 
syphilis,  44-46. 

Tabetic  palsies,  nature  of,  87. 

Therapeutic  test,  limitations  of, 
availability  of,  in  syphilitic 
chronic  cerebral  meningitis,  68. 

Tissue  formations  due  to  syphilis, 
pathology,  position  and  char- 
acter of,  13-16. 

Treatment  of  syphilitic  inflam- 
mations, better  by  mercury 
than  by  iodides,  117. 


PRINTEDINU.S.A. 


minium  iiui  inn  mil  ii »> 

A  000510435 


WC165 
G?23s 
1892 
Cowers,  William  R 

Syphilis  and  the  nervous  sy 


DATE 


ISSUED    TO 


WC165 
GT23s 

1892 
Govern ,  William  R 

Syplilis  and  the  nervous  system 


MEDICAL  SCIENCES  LIBRARY 

UNIVERSITY  OF  CALIFORNIA,  IRVINE 

IRVINE,  CALIFORNIA  92664 


